There are many types of batteries, and commonly used batteries are mainly dry batteries, batteries , and small batteries. In addition, there are metal-air batteries, fuel cells, and other energy conversion batteries such as solar cells, thermoelectric cells, and nuclear batteries.
Dry batteries A commonly used one is a carbon-zinc dry battery (Figure 3). The negative electrode is a cylinder made of zinc, which contains ammonium chloride as an electrolyte, a small amount of zinc chloride, an inert filler and a paste-like electrolyte prepared by water. The positive electrode is a carbon surrounded by a paste electrolyte doped with manganese dioxide. Baton. The electrode reaction is such that the zinc atom at the negative electrode becomes zinc ion (Zn++), and electrons are released, and the ammonium ion (NH嬃) at the positive electrode obtains electrons and becomes ammonia gas and hydrogen gas. The hydrogen dioxide is used to drive off the hydrogen to eliminate the polarization. The electromotive force is about 1.5 volts.
There are many types of batteries, and the common feature is that they can undergo multiple charging and discharging cycles and are used repeatedly.
Lead storage batteries are most commonly used. The plates are made of lead alloy and the electrolyte is dilute sulfuric acid. Both plates are covered with lead sulfate. However, after charging, the lead sulfate on the positive electrode plate is converted into lead dioxide, and the lead sulfate at the negative electrode is converted into metal lead. When discharging, a chemical reaction in the opposite direction occurs.
Lead-acid batteries have an electromotive force of about 2 volts and are commonly used in series to form a battery pack of 6 volts or 12 volts. When the battery is discharged, the concentration of sulfuric acid is reduced, and the method of measuring the specific gravity of the electrolyte can be used to determine whether the battery needs to be charged or whether the charging process can be ended.
The advantage of the lead storage battery is that the electromotive force is relatively stable during discharge, and the disadvantage is that it is smaller than the energy (the electric energy stored per unit weight) and is highly corrosive to the environment.
It consists of a positive electrode plate group, a negative electrode plate group, an electrolyte solution, a container, and the like. The charged positive electrode plate is brown lead dioxide (PbO2), and the negative electrode plate is gray fleece lead (Pb). When the two plates are placed in a concentration of 27% to 37% sulfuric acid (H2SO4) aqueous solution, the pole The lead and sulfuric acid of the plate react chemically, and the divalent lead cation (Pb2+) is transferred to the electrolyte, leaving two electrons (2e-) on the negative plate. Due to the gravitational pull of positive and negative charges, lead positive ions accumulate around the negative electrode plate, while the positive electrode plate has a small amount of lead dioxide (PbO2) penetrating into the electrolyte under the action of water molecules in the electrolyte, wherein the two valence oxygen ions and water combine To make the lead dioxide molecule an unstable substance that can be dissociated - lead hydroxide [Pb(OH4]). Lead hydroxide consists of a tetravalent lead cation (Pb4+) and four hydroxy groups [4(OH)-]. The tetravalent lead positive ion (Pb4+) is left on the positive electrode plate to positively charge the positive electrode plate. Since the negative plate is negatively charged, a certain potential difference is generated between the two plates, which is the electromotive force of the battery. When the external circuit is turned on, the current flows from the positive electrode to the negative electrode. During the discharge process, the electrons on the negative electrode plate continuously flow to the positive electrode plate through the external circuit. At this time, the electrolyte is ionized into hydrogen positive ions (H+) and sulfate negative ions (SO42-) in the electrolyte, under the action of the ionic electric field. The two ions move to the positive and negative electrodes respectively, and the sulfate negative ions reach the negative electrode plate and combine with lead positive ions to form lead sulfate (PbSO4). On the positive electrode plate, due to the inflow of electrons from an external circuit, a tetravalent lead positive ion (Pb4+) is synthesized to synthesize a divalent lead positive ion (Pb2+), and immediately combines with a sulfate anion near the positive electrode plate to form lead sulfate adhesion. On the positive electrode.
As the battery is discharged, both the positive and negative plates are vulcanized, and the sulfuric acid in the electrolyte is gradually reduced, and the water is increased, thereby causing the specific gravity of the electrolyte to decrease. In actual use, the specific gravity of the electrolyte can be determined to determine the battery. The degree of discharge. Under normal use, the lead storage battery should not be over-discharged, otherwise the fine lead sulfate crystal mixed with the active material will be formed into a larger body, which not only increases the resistance of the plate but also makes it difficult to recharge it during charging. The reduction directly affects the capacity and life of the reservoir. Lead battery charging is the reverse of the discharge process.
Lead storage batteries have a wide operating voltage, a wide range of operating temperatures and current ranges, hundreds of cycles of charge and discharge, good storage performance (especially suitable for dry charge storage), and low cost. The use of new lead alloys can improve the performance of lead storage batteries. If lead-calcium alloy is used as the grid, the minimum float current of the lead battery can be ensured, the water supply can be reduced and the service life can be prolonged. The use of lead-lithium alloy casting the positive grid can reduce the self-discharge and meet the sealing requirements. In addition, the open lead storage battery should be gradually changed to a sealed type, and an acid-proof, explosion-proof and dehydrogenated lead storage battery should be developed.
Lead-crystal battery Lead-crystal battery is a proprietary technology. The high-conductive silicate electrolyte used is a complex modification of the traditional lead-acid battery electrolyte. The acid-free internalization process is an innovation of the shaping process. These technical processes are the first of its kind at home and abroad. The products have no pollution problems in production, use and waste, and are more in line with environmental protection requirements. Because lead-crystal batteries use silicate instead of sulfuric acid solution as electrolyte, they overcome lead-acid batteries. Short-lived, can not be a series of shortcomings of large current charge and discharge, more in line with the necessary conditions of the power battery, lead-crystal battery will also have a huge impetus to the field of power batteries.
Lead-crystal batteries have unparalleled advantages over lead-acid batteries:
1. The service life of lead-crystal battery is generally about 350 times. The lead-type battery has a cycle life of more than 700 times under the premise of 60% discharge of rated capacity, which is equivalent to the life of lead-acid battery. Times.
2. High rate discharge performance The special process makes the lead crystal battery have high rate discharge characteristics. Generally, the lead acid battery discharge is only 3C, and the lead crystal battery discharge can reach 10C.
3, deep discharge performance is good Lead crystal battery can be deeply discharged to 0V, continue to charge can restore all rated capacity, this feature is difficult to achieve relative to lead-acid batteries.
4, good low temperature resistance Lead crystal battery temperature range is wide, from -20-50 ° C can adapt, especially in the case of -20 ° C, the discharge can reach 87%. It is a rare choice for the vast low temperature areas.
5. Good environmental protection The new materials, new processes and new formulas used in lead-crystal batteries do not contain harmful substances such as acid mist, which will not cause pollution to land, rivers, etc., and are more in line with environmental protection requirements.
Iron-nickel batteries are also called Edison batteries. Unlike lead acid batteries, which are acidic batteries, the electrolyte of iron-nickel batteries is an alkaline potassium hydroxide solution, which is an alkaline storage battery. The positive electrode is nickel oxide and the negative electrode is iron. The chemical reaction for charging and discharging is an electromotive force of about 1.3 to 1.4 volts. Its advantages are light weight, long life and easy maintenance. The disadvantage is that the efficiency is not high.
Nickel-cadmium storage battery The positive electrode is nickel hydroxide, the negative electrode is cadmium, and the electrolyte is potassium hydroxide solution. The chemical reaction of charging and discharging is that it is light, shockproof and has a long service life, and is often used in small electronic equipment.
Silver-zinc battery The positive electrode is silver oxide, the negative electrode is zinc, and the electrolyte is potassium hydroxide solution.
The silver-zinc battery has a large specific energy, can discharge at a large current, is shock-resistant, and is used as a power source for space navigation, satellites, rockets, and the like. The number of charge and discharge can reach about 100 to 150 cycles. The disadvantage is that it is expensive and has a short service life.
Fuel cell A device that directly converts the chemical energy released by a fuel during combustion into electrical energy. The difference from the battery is that it can continuously replenish fuel and oxidant from the outside to the two electrode regions without charging. The fuel cell is composed of four parts: a fuel (for example, hydrogen, methane, etc.), an oxidant (such as oxygen and air), an electrode, and an electrolyte. The electrode has catalytic properties and is porous to ensure a large active area. In operation, the fuel is passed to the negative electrode, and the oxidant is passed to the positive electrode, and each of them is electrochemically reacted under the catalysis of the electrode to obtain electric energy.
The fuel cell directly converts the energy released by the combustion reaction into electrical energy, so its energy utilization rate is high, which is about twice the efficiency of the heat engine. In addition, it has the following advantages: 1 equipment is light; 2 no noise, less pollution; 3 can run continuously; 4 unit weight output power is high. Therefore, it has been applied in space navigation and has shown wide application prospects in various fields of military and civilian use.
Solar cell A device that converts the energy of sunlight into electrical energy. When sunlight is irradiated, a terminal voltage is generated to obtain a current, and a solar cell used in a satellite or a spacecraft is made of a semiconductor (a commonly used silicon photo cell). When sunlight is applied to the surface of the solar cell, a potential difference is formed on both sides of the semiconductor PN junction. Its efficiency is above 10%, and the typical output power is 5-10 milliwatts per square centimeter (junction area).
Temperature difference battery When two kinds of metals are connected to a closed circuit and maintain different temperatures at the two joints, an electromotive force, that is, a temperature difference electromotive force is generated. This is called the Seebeck effect (see thermoelectric phenomenon). This device is called a thermocouple or a thermocouple. Metal thermocouples produce a small temperature difference with a small electromotive force that is commonly used to measure temperature differences. However, when the thermocouples are connected in series to form a thermopile, they can also be used as a low-power source. This is called a thermoelectric battery. A thermoelectric battery made of a semiconductor material has a strong thermoelectric effect.
Nuclear cell A device that converts nuclear energy directly into electrical energy (current nuclear power plants use nuclear fission energy to heat steam to propel the generator to generate electricity, and nuclear energy released during nuclear fission cannot be directly converted into electrical energy). A typical nuclear battery includes a radioactive source that radiates beta rays (high-speed electron currents) (e.g., helium-90), a current collector that collects these electrons, and three parts of the insulator through which the electrons pass from the radioactive source to the current collector. One end of the radioactive source becomes a positive electrode due to loss of negative electric power, and one end of the current collector is negatively charged to become a negative electrode. A potential difference is formed between the radioactive source and the electrodes at both ends of the current collector. This type of nuclear battery can generate high voltage, but the current is small. It is used in satellites and spacecraft for long-term use.
After the primary battery is discharged (continuously or intermittently) until the battery capacity is exhausted, it can no longer be effectively restored to the battery before the discharge by the charging method. Features are easy to carry, no maintenance, and can be stored or used for long periods of time (months or even years). The primary batteries mainly include zinc-manganese batteries, zinc-mercury batteries, zinc-air batteries, solid electrolyte batteries, and lithium batteries. Zinc-manganese batteries are divided into dry batteries and alkaline batteries.
Zinc-manganese dry batteries are the earliest and still mass-produced primary batteries. There are two types of cylindrical and laminated structures. Its characteristics are easy to use, low price, abundant raw material sources, suitable for a large number of automated production. However, the discharge voltage is not stable enough, and the capacity is greatly affected by the discharge rate. Suitable for small to medium discharge rate and intermittent discharge. The new zinc-manganese dry battery uses a high-concentration zinc chloride electrolyte, an excellent manganese dioxide powder and a paperboard layer structure to double the capacity and life and improve the sealing performance.
Alkaline zinc-manganese battery A zinc-manganese battery that replaces a neutral electrolyte with an alkaline electrolyte. Available in cylindrical and button styles. The advantages of this type of battery are large capacity, stable voltage, continuous discharge at high current, and operation at low temperatures (-40 ° C). This battery can be charged and discharged dozens of times under specified conditions.
Zinc-mercury battery was invented by S. Robin of the United States, hence the name Robin Battery. It was the first small battery invented. Available in button type and cylindrical type. The discharge voltage is stable and can be used as a voltage standard that is less demanding. The disadvantage is poor low temperature performance (can only be used above 0 °C) and mercury is toxic. Zinc-mercury batteries have gradually been replaced by other series of batteries.
Zinc air battery The oxygen in the air is the positive electrode active material, so the specific capacity is large. There are two series of alkaline and neutral, and there are two types of structure: wet and dry. The wet battery is only alkaline, and the NaOH is used as the electrolyte. The price is low, and a large capacity (100 ampere-hour or more) fixed battery is used for the railway signal. Dry batteries are available in both alkaline and neutral. Neutral air dry batteries are rich in raw materials and low in price, but can only work at low currents. The alkaline air dry battery can discharge at a large current, and has a larger specific energy, and the continuous discharge performance is better than the intermittent discharge performance. All air dry batteries are affected by ambient humidity, have a short service life, and have poor reliability and cannot be used in a sealed state.
Solid electrolyte battery A solid ion conductor is used as an electrolyte, and it is classified into two types: high temperature and normal temperature. High-temperature sodium-sulfur batteries can work at high currents. At room temperature, there is a silver iodine battery with a voltage of 0.6 volts, which is expensive and has not yet been applied. A lithium iodine battery has been used with a voltage of 2.7 volts. This battery is highly reliable and can be used in pacemakers. However, this battery discharge current can only reach the micro-ampere level.
Lithium battery A battery with lithium as the negative electrode. It is a new high-energy battery developed after the 1960s. According to the electrolyte used, it is divided into: 1 high temperature molten salt lithium battery; 2 organic electrolyte lithium battery; 3 inorganic nonaqueous electrolyte lithium battery; 4 solid electrolyte lithium battery; 5 lithium water battery. The advantage of the lithium battery is that the single battery has high voltage, large specific energy, long storage life (up to 10 years), high and low temperature performance, and can be used at -40 to 150 °C. The disadvantage is that it is expensive and not safe. In addition, voltage lag and safety issues need to be improved. In recent years, the development of power batteries and new cathode materials, especially the development of lithium iron phosphate materials, has greatly contributed to the development of lithium batteries.
There are two ways to activate the battery. One is to store the electrolyte separately from the electrode. It is activated by injecting the electrolyte into the battery pack before use, such as magnesium seawater batteries, reserve chromic acid batteries, and zinc-silver batteries. The other is to use a molten salt electrolyte. The electrolyte is not conductive at normal temperature, and the electrolyte is activated by rapidly igniting the heating agent before use, which is called a heat battery. The battery can be made of calcium, magnesium or lithium alloy as the negative electrode, the eutectic of KCl and LiCl is the electrolyte, CaCrO4, PbSO4 or V2O5 is the positive electrode, and the zirconium powder or the iron powder is used as the heating agent. Long-term storage (more than 10 years) with a fully sealed structure. The reserve battery is suitable for special purposes.
Standard batteries The most famous is the Wheatstone standard battery, which is divided into saturated and unsaturated. Its standard electromotive force is 1.01864 volts (20 ° C). The temperature coefficient of the unsaturated type is about 1/4 of the saturated type.
The paste type zinc-manganese dry battery is composed of a zinc tube, an electric paste layer, a manganese dioxide positive electrode, a carbon rod, a copper cap and the like. The outermost layer is the zinc cylinder, which is both the negative pole of the battery and the container. It is gradually dissolved during the discharge process; the center is a collecting carbon rod; the carbon rod is tightly wrapped around it. A mixture of dark brown or black manganese dioxide powder and a conductive material (graphite or acetylene black) which, together with the carbon rod, constitutes the positive electrode of the battery, also called a carbon pack. To avoid evaporation of moisture, the upper part of the dry battery is sealed with paraffin or asphalt. The electrode reaction in the operation of zinc-manganese dry battery is zinc electrode: Zn→Zn2++2e
The cardboard type zinc-manganese dry battery is improved on the basis of a paste type zinc-manganese dry battery. It is based on high-quality kraft paper with a thickness of 70-100 microns and free of metal impurities. The surface is coated with a tuned paste and then dried to form a cardboard instead of paste in a paste-type zinc-manganese dry battery. Electrolyte layer. The actual discharge capacity of the cardboard type zinc-manganese dry battery is 2 to 3 times higher than that of the conventional paste type zinc-manganese dry battery. Most of the dry batteries labeled "High Performance" are cardboard.
Alkaline zinc-manganese dry battery The electrolyte is formed by amalgamating zinc powder, 35% potassium hydroxide solution and some sodium carboxymethyl cellulose. Since the potassium hydroxide solution has a low freezing point and a small internal resistance, the alkaline zinc-manganese dry battery can operate at a temperature of -20 ° C and can discharge at a large current. Alkaline zinc-manganese dry batteries can be charged and discharged more than 40 times, but deep discharge cannot be performed before charging (retaining 60% to 70% of capacity), and the charging current and the end of charging period must be strictly controlled.
The laminated zinc-manganese dry battery is composed of several compact flat cell units stacked together. Each unit cell consists of a plastic case, zinc skin, conductive film, and separator paper, carbon cake (positive electrode). The separator paper is a pulp paper having a starch layer on the surface of the electrolyte, which is attached to the zinc skin; the carbon paper cake is on the separator paper. The separator paper is like the electric paste layer of the paste dry battery, and functions to isolate the zinc skin anode and the carbon cake anode. The laminated zinc-manganese dry battery has the trouble of serially combining the cylindrical paste type dry batteries, and has a compact structure, a small volume, and a large volume specific capacity, but the storage life is short and the internal resistance is large, so the discharge current should not be too large.
Alkaline storage batteries Compared with lead storage batteries of the same capacity, they have a small size, long life and high current discharge, but at a higher cost. Alkaline batteries are divided into iron-nickel, cadmium-nickel, zinc-silver batteries and other series according to the active material of the plates. Taking a cadmium-nickel battery as an example, the working principle of an alkaline storage battery is: after the active material of the battery plate is charged, the positive plate is nickel hydroxide [Ni(OH)3], and the negative plate is metal cadmium (Cd); At the termination, the positive electrode plate is converted into nickel oxyhydroxide [Ni(OH2)], the negative electrode plate is converted into cadmium hydroxide [Cd(OH)2], and the electrolyte is mostly selected from potassium hydroxide (KOH) solution.
Metal-air battery A high-energy battery in which oxygen in the air is used as a positive electrode active material and metal is used as a negative electrode active material. The metal used is generally magnesium, aluminum, zinc, cadmium, iron, etc.; the electrolyte is an aqueous solution. Among them, zinc-air batteries have become mature products.
Metal-air batteries have a higher specific energy because air is not counted within the weight of the battery. The specific energy of the zinc-air battery is the highest among the currently produced batteries, which has reached 400 watt-hours/kg (Wh/kg). It is a high-performance medium-power battery and is developing in the direction of high-power batteries. The metal-air battery currently produced is mainly a primary battery; the secondary metal-air battery under development is a mechanical rechargeable battery using a metal electrode replacement. Since the metal-air battery is constantly supplied with air, it cannot operate in a sealed state or in an air-deficient environment. In addition, the electrolyte solution in the battery is susceptible to the influence of the humidity of the air to degrade the performance of the battery; the oxygen in the air passes through the air electrode and diffuses to the metal electrode, forming a corroded battery to cause self-discharge.
The nano cell is 10-9 meters, and the nano cell is a battery made of nano materials (such as nano MnO2, LiMn2O4, Ni(OH)2, etc.), and the nano material has special microstructure and physical and chemical properties (such as quantum size effect, Surface effect and tunnel quantum effect, etc. At present, the mature nano-battery of domestic technology is a nano-activated carbon fiber battery, which is mainly used in electric vehicles, electric motorcycles and electric bicycles. The battery can be charged and cycled 1000 times, and used continuously for about 10 years. Charging takes only about 20 minutes, the flat road travels up to 400km, and the weight is 128kg, which has surpassed the battery level of countries such as the US and Japan. The Ni-MH battery produced by them requires about 6-8 hours of flat road travel for 300km.
Dry batteries A commonly used one is a carbon-zinc dry battery (Figure 3). The negative electrode is a cylinder made of zinc, which contains ammonium chloride as an electrolyte, a small amount of zinc chloride, an inert filler and a paste-like electrolyte prepared by water. The positive electrode is a carbon surrounded by a paste electrolyte doped with manganese dioxide. Baton. The electrode reaction is such that the zinc atom at the negative electrode becomes zinc ion (Zn++), and electrons are released, and the ammonium ion (NH嬃) at the positive electrode obtains electrons and becomes ammonia gas and hydrogen gas. The hydrogen dioxide is used to drive off the hydrogen to eliminate the polarization. The electromotive force is about 1.5 volts.
There are many types of batteries, and the common feature is that they can undergo multiple charging and discharging cycles and are used repeatedly.
Lead storage batteries are most commonly used. The plates are made of lead alloy and the electrolyte is dilute sulfuric acid. Both plates are covered with lead sulfate. However, after charging, the lead sulfate on the positive electrode plate is converted into lead dioxide, and the lead sulfate at the negative electrode is converted into metal lead. When discharging, a chemical reaction in the opposite direction occurs.
Lead-acid batteries have an electromotive force of about 2 volts and are commonly used in series to form a battery pack of 6 volts or 12 volts. When the battery is discharged, the concentration of sulfuric acid is reduced, and the method of measuring the specific gravity of the electrolyte can be used to determine whether the battery needs to be charged or whether the charging process can be ended.
The advantage of the lead storage battery is that the electromotive force is relatively stable during discharge, and the disadvantage is that it is smaller than the energy (the electric energy stored per unit weight) and is highly corrosive to the environment.
It consists of a positive electrode plate group, a negative electrode plate group, an electrolyte solution, a container, and the like. The charged positive electrode plate is brown lead dioxide (PbO2), and the negative electrode plate is gray fleece lead (Pb). When the two plates are placed in a concentration of 27% to 37% sulfuric acid (H2SO4) aqueous solution, the pole The lead and sulfuric acid of the plate react chemically, and the divalent lead cation (Pb2+) is transferred to the electrolyte, leaving two electrons (2e-) on the negative plate. Due to the gravitational pull of positive and negative charges, lead positive ions accumulate around the negative electrode plate, while the positive electrode plate has a small amount of lead dioxide (PbO2) penetrating into the electrolyte under the action of water molecules in the electrolyte, wherein the two valence oxygen ions and water combine To make the lead dioxide molecule an unstable substance that can be dissociated - lead hydroxide [Pb(OH4]). Lead hydroxide consists of a tetravalent lead cation (Pb4+) and four hydroxy groups [4(OH)-]. The tetravalent lead positive ion (Pb4+) is left on the positive electrode plate to positively charge the positive electrode plate. Since the negative plate is negatively charged, a certain potential difference is generated between the two plates, which is the electromotive force of the battery. When the external circuit is turned on, the current flows from the positive electrode to the negative electrode. During the discharge process, the electrons on the negative electrode plate continuously flow to the positive electrode plate through the external circuit. At this time, the electrolyte is ionized into hydrogen positive ions (H+) and sulfate negative ions (SO42-) in the electrolyte, under the action of the ionic electric field. The two ions move to the positive and negative electrodes respectively, and the sulfate negative ions reach the negative electrode plate and combine with lead positive ions to form lead sulfate (PbSO4). On the positive electrode plate, due to the inflow of electrons from an external circuit, a tetravalent lead positive ion (Pb4+) is synthesized to synthesize a divalent lead positive ion (Pb2+), and immediately combines with a sulfate anion near the positive electrode plate to form lead sulfate adhesion. On the positive electrode.
As the battery is discharged, both the positive and negative plates are vulcanized, and the sulfuric acid in the electrolyte is gradually reduced, and the water is increased, thereby causing the specific gravity of the electrolyte to decrease. In actual use, the specific gravity of the electrolyte can be determined to determine the battery. The degree of discharge. Under normal use, the lead storage battery should not be over-discharged, otherwise the fine lead sulfate crystal mixed with the active material will be formed into a larger body, which not only increases the resistance of the plate but also makes it difficult to recharge it during charging. The reduction directly affects the capacity and life of the reservoir. Lead battery charging is the reverse of the discharge process.
Lead storage batteries have a wide operating voltage, a wide range of operating temperatures and current ranges, hundreds of cycles of charge and discharge, good storage performance (especially suitable for dry charge storage), and low cost. The use of new lead alloys can improve the performance of lead storage batteries. If lead-calcium alloy is used as the grid, the minimum float current of the lead battery can be ensured, the water supply can be reduced and the service life can be prolonged. The use of lead-lithium alloy casting the positive grid can reduce the self-discharge and meet the sealing requirements. In addition, the open lead storage battery should be gradually changed to a sealed type, and an acid-proof, explosion-proof and dehydrogenated lead storage battery should be developed.
Lead-crystal battery Lead-crystal battery is a proprietary technology. The high-conductive silicate electrolyte used is a complex modification of the traditional lead-acid battery electrolyte. The acid-free internalization process is an innovation of the shaping process. These technical processes are the first of its kind at home and abroad. The products have no pollution problems in production, use and waste, and are more in line with environmental protection requirements. Because lead-crystal batteries use silicate instead of sulfuric acid solution as electrolyte, they overcome lead-acid batteries. Short-lived, can not be a series of shortcomings of large current charge and discharge, more in line with the necessary conditions of the power battery, lead-crystal battery will also have a huge impetus to the field of power batteries.
Lead-crystal batteries have unparalleled advantages over lead-acid batteries:
1. The service life of lead-crystal battery is generally about 350 times. The lead-type battery has a cycle life of more than 700 times under the premise of 60% discharge of rated capacity, which is equivalent to the life of lead-acid battery. Times.
2. High rate discharge performance The special process makes the lead crystal battery have high rate discharge characteristics. Generally, the lead acid battery discharge is only 3C, and the lead crystal battery discharge can reach 10C.
3, deep discharge performance is good Lead crystal battery can be deeply discharged to 0V, continue to charge can restore all rated capacity, this feature is difficult to achieve relative to lead-acid batteries.
4, good low temperature resistance Lead crystal battery temperature range is wide, from -20-50 ° C can adapt, especially in the case of -20 ° C, the discharge can reach 87%. It is a rare choice for the vast low temperature areas.
5. Good environmental protection The new materials, new processes and new formulas used in lead-crystal batteries do not contain harmful substances such as acid mist, which will not cause pollution to land, rivers, etc., and are more in line with environmental protection requirements.
Iron-nickel batteries are also called Edison batteries. Unlike lead acid batteries, which are acidic batteries, the electrolyte of iron-nickel batteries is an alkaline potassium hydroxide solution, which is an alkaline storage battery. The positive electrode is nickel oxide and the negative electrode is iron. The chemical reaction for charging and discharging is an electromotive force of about 1.3 to 1.4 volts. Its advantages are light weight, long life and easy maintenance. The disadvantage is that the efficiency is not high.
Nickel-cadmium storage battery The positive electrode is nickel hydroxide, the negative electrode is cadmium, and the electrolyte is potassium hydroxide solution. The chemical reaction of charging and discharging is that it is light, shockproof and has a long service life, and is often used in small electronic equipment.
Silver-zinc battery The positive electrode is silver oxide, the negative electrode is zinc, and the electrolyte is potassium hydroxide solution.
The silver-zinc battery has a large specific energy, can discharge at a large current, is shock-resistant, and is used as a power source for space navigation, satellites, rockets, and the like. The number of charge and discharge can reach about 100 to 150 cycles. The disadvantage is that it is expensive and has a short service life.
Fuel cell A device that directly converts the chemical energy released by a fuel during combustion into electrical energy. The difference from the battery is that it can continuously replenish fuel and oxidant from the outside to the two electrode regions without charging. The fuel cell is composed of four parts: a fuel (for example, hydrogen, methane, etc.), an oxidant (such as oxygen and air), an electrode, and an electrolyte. The electrode has catalytic properties and is porous to ensure a large active area. In operation, the fuel is passed to the negative electrode, and the oxidant is passed to the positive electrode, and each of them is electrochemically reacted under the catalysis of the electrode to obtain electric energy.
The fuel cell directly converts the energy released by the combustion reaction into electrical energy, so its energy utilization rate is high, which is about twice the efficiency of the heat engine. In addition, it has the following advantages: 1 equipment is light; 2 no noise, less pollution; 3 can run continuously; 4 unit weight output power is high. Therefore, it has been applied in space navigation and has shown wide application prospects in various fields of military and civilian use.
Solar cell A device that converts the energy of sunlight into electrical energy. When sunlight is irradiated, a terminal voltage is generated to obtain a current, and a solar cell used in a satellite or a spacecraft is made of a semiconductor (a commonly used silicon photo cell). When sunlight is applied to the surface of the solar cell, a potential difference is formed on both sides of the semiconductor PN junction. Its efficiency is above 10%, and the typical output power is 5-10 milliwatts per square centimeter (junction area).
Temperature difference battery When two kinds of metals are connected to a closed circuit and maintain different temperatures at the two joints, an electromotive force, that is, a temperature difference electromotive force is generated. This is called the Seebeck effect (see thermoelectric phenomenon). This device is called a thermocouple or a thermocouple. Metal thermocouples produce a small temperature difference with a small electromotive force that is commonly used to measure temperature differences. However, when the thermocouples are connected in series to form a thermopile, they can also be used as a low-power source. This is called a thermoelectric battery. A thermoelectric battery made of a semiconductor material has a strong thermoelectric effect.
Nuclear cell A device that converts nuclear energy directly into electrical energy (current nuclear power plants use nuclear fission energy to heat steam to propel the generator to generate electricity, and nuclear energy released during nuclear fission cannot be directly converted into electrical energy). A typical nuclear battery includes a radioactive source that radiates beta rays (high-speed electron currents) (e.g., helium-90), a current collector that collects these electrons, and three parts of the insulator through which the electrons pass from the radioactive source to the current collector. One end of the radioactive source becomes a positive electrode due to loss of negative electric power, and one end of the current collector is negatively charged to become a negative electrode. A potential difference is formed between the radioactive source and the electrodes at both ends of the current collector. This type of nuclear battery can generate high voltage, but the current is small. It is used in satellites and spacecraft for long-term use.
After the primary battery is discharged (continuously or intermittently) until the battery capacity is exhausted, it can no longer be effectively restored to the battery before the discharge by the charging method. Features are easy to carry, no maintenance, and can be stored or used for long periods of time (months or even years). The primary batteries mainly include zinc-manganese batteries, zinc-mercury batteries, zinc-air batteries, solid electrolyte batteries, and lithium batteries. Zinc-manganese batteries are divided into dry batteries and alkaline batteries.
Zinc-manganese dry batteries are the earliest and still mass-produced primary batteries. There are two types of cylindrical and laminated structures. Its characteristics are easy to use, low price, abundant raw material sources, suitable for a large number of automated production. However, the discharge voltage is not stable enough, and the capacity is greatly affected by the discharge rate. Suitable for small to medium discharge rate and intermittent discharge. The new zinc-manganese dry battery uses a high-concentration zinc chloride electrolyte, an excellent manganese dioxide powder and a paperboard layer structure to double the capacity and life and improve the sealing performance.
Alkaline zinc-manganese battery A zinc-manganese battery that replaces a neutral electrolyte with an alkaline electrolyte. Available in cylindrical and button styles. The advantages of this type of battery are large capacity, stable voltage, continuous discharge at high current, and operation at low temperatures (-40 ° C). This battery can be charged and discharged dozens of times under specified conditions.
Zinc-mercury battery was invented by S. Robin of the United States, hence the name Robin Battery. It was the first small battery invented. Available in button type and cylindrical type. The discharge voltage is stable and can be used as a voltage standard that is less demanding. The disadvantage is poor low temperature performance (can only be used above 0 °C) and mercury is toxic. Zinc-mercury batteries have gradually been replaced by other series of batteries.
Zinc air battery The oxygen in the air is the positive electrode active material, so the specific capacity is large. There are two series of alkaline and neutral, and there are two types of structure: wet and dry. The wet battery is only alkaline, and the NaOH is used as the electrolyte. The price is low, and a large capacity (100 ampere-hour or more) fixed battery is used for the railway signal. Dry batteries are available in both alkaline and neutral. Neutral air dry batteries are rich in raw materials and low in price, but can only work at low currents. The alkaline air dry battery can discharge at a large current, and has a larger specific energy, and the continuous discharge performance is better than the intermittent discharge performance. All air dry batteries are affected by ambient humidity, have a short service life, and have poor reliability and cannot be used in a sealed state.
Solid electrolyte battery A solid ion conductor is used as an electrolyte, and it is classified into two types: high temperature and normal temperature. High-temperature sodium-sulfur batteries can work at high currents. At room temperature, there is a silver iodine battery with a voltage of 0.6 volts, which is expensive and has not yet been applied. A lithium iodine battery has been used with a voltage of 2.7 volts. This battery is highly reliable and can be used in pacemakers. However, this battery discharge current can only reach the micro-ampere level.
Lithium battery A battery with lithium as the negative electrode. It is a new high-energy battery developed after the 1960s. According to the electrolyte used, it is divided into: 1 high temperature molten salt lithium battery; 2 organic electrolyte lithium battery; 3 inorganic nonaqueous electrolyte lithium battery; 4 solid electrolyte lithium battery; 5 lithium water battery. The advantage of the lithium battery is that the single battery has high voltage, large specific energy, long storage life (up to 10 years), high and low temperature performance, and can be used at -40 to 150 °C. The disadvantage is that it is expensive and not safe. In addition, voltage lag and safety issues need to be improved. In recent years, the development of power batteries and new cathode materials, especially the development of lithium iron phosphate materials, has greatly contributed to the development of lithium batteries.
There are two ways to activate the battery. One is to store the electrolyte separately from the electrode. It is activated by injecting the electrolyte into the battery pack before use, such as magnesium seawater batteries, reserve chromic acid batteries, and zinc-silver batteries. The other is to use a molten salt electrolyte. The electrolyte is not conductive at normal temperature, and the electrolyte is activated by rapidly igniting the heating agent before use, which is called a heat battery. The battery can be made of calcium, magnesium or lithium alloy as the negative electrode, the eutectic of KCl and LiCl is the electrolyte, CaCrO4, PbSO4 or V2O5 is the positive electrode, and the zirconium powder or the iron powder is used as the heating agent. Long-term storage (more than 10 years) with a fully sealed structure. The reserve battery is suitable for special purposes.
Standard batteries The most famous is the Wheatstone standard battery, which is divided into saturated and unsaturated. Its standard electromotive force is 1.01864 volts (20 ° C). The temperature coefficient of the unsaturated type is about 1/4 of the saturated type.
The paste type zinc-manganese dry battery is composed of a zinc tube, an electric paste layer, a manganese dioxide positive electrode, a carbon rod, a copper cap and the like. The outermost layer is the zinc cylinder, which is both the negative pole of the battery and the container. It is gradually dissolved during the discharge process; the center is a collecting carbon rod; the carbon rod is tightly wrapped around it. A mixture of dark brown or black manganese dioxide powder and a conductive material (graphite or acetylene black) which, together with the carbon rod, constitutes the positive electrode of the battery, also called a carbon pack. To avoid evaporation of moisture, the upper part of the dry battery is sealed with paraffin or asphalt. The electrode reaction in the operation of zinc-manganese dry battery is zinc electrode: Zn→Zn2++2e
The cardboard type zinc-manganese dry battery is improved on the basis of a paste type zinc-manganese dry battery. It is based on high-quality kraft paper with a thickness of 70-100 microns and free of metal impurities. The surface is coated with a tuned paste and then dried to form a cardboard instead of paste in a paste-type zinc-manganese dry battery. Electrolyte layer. The actual discharge capacity of the cardboard type zinc-manganese dry battery is 2 to 3 times higher than that of the conventional paste type zinc-manganese dry battery. Most of the dry batteries labeled "High Performance" are cardboard.
Alkaline zinc-manganese dry battery The electrolyte is formed by amalgamating zinc powder, 35% potassium hydroxide solution and some sodium carboxymethyl cellulose. Since the potassium hydroxide solution has a low freezing point and a small internal resistance, the alkaline zinc-manganese dry battery can operate at a temperature of -20 ° C and can discharge at a large current. Alkaline zinc-manganese dry batteries can be charged and discharged more than 40 times, but deep discharge cannot be performed before charging (retaining 60% to 70% of capacity), and the charging current and the end of charging period must be strictly controlled.
The laminated zinc-manganese dry battery is composed of several compact flat cell units stacked together. Each unit cell consists of a plastic case, zinc skin, conductive film, and separator paper, carbon cake (positive electrode). The separator paper is a pulp paper having a starch layer on the surface of the electrolyte, which is attached to the zinc skin; the carbon paper cake is on the separator paper. The separator paper is like the electric paste layer of the paste dry battery, and functions to isolate the zinc skin anode and the carbon cake anode. The laminated zinc-manganese dry battery has the trouble of serially combining the cylindrical paste type dry batteries, and has a compact structure, a small volume, and a large volume specific capacity, but the storage life is short and the internal resistance is large, so the discharge current should not be too large.
Alkaline storage batteries Compared with lead storage batteries of the same capacity, they have a small size, long life and high current discharge, but at a higher cost. Alkaline batteries are divided into iron-nickel, cadmium-nickel, zinc-silver batteries and other series according to the active material of the plates. Taking a cadmium-nickel battery as an example, the working principle of an alkaline storage battery is: after the active material of the battery plate is charged, the positive plate is nickel hydroxide [Ni(OH)3], and the negative plate is metal cadmium (Cd); At the termination, the positive electrode plate is converted into nickel oxyhydroxide [Ni(OH2)], the negative electrode plate is converted into cadmium hydroxide [Cd(OH)2], and the electrolyte is mostly selected from potassium hydroxide (KOH) solution.
Metal-air battery A high-energy battery in which oxygen in the air is used as a positive electrode active material and metal is used as a negative electrode active material. The metal used is generally magnesium, aluminum, zinc, cadmium, iron, etc.; the electrolyte is an aqueous solution. Among them, zinc-air batteries have become mature products.
Metal-air batteries have a higher specific energy because air is not counted within the weight of the battery. The specific energy of the zinc-air battery is the highest among the currently produced batteries, which has reached 400 watt-hours/kg (Wh/kg). It is a high-performance medium-power battery and is developing in the direction of high-power batteries. The metal-air battery currently produced is mainly a primary battery; the secondary metal-air battery under development is a mechanical rechargeable battery using a metal electrode replacement. Since the metal-air battery is constantly supplied with air, it cannot operate in a sealed state or in an air-deficient environment. In addition, the electrolyte solution in the battery is susceptible to the influence of the humidity of the air to degrade the performance of the battery; the oxygen in the air passes through the air electrode and diffuses to the metal electrode, forming a corroded battery to cause self-discharge.
The nano cell is 10-9 meters, and the nano cell is a battery made of nano materials (such as nano MnO2, LiMn2O4, Ni(OH)2, etc.), and the nano material has special microstructure and physical and chemical properties (such as quantum size effect, Surface effect and tunnel quantum effect, etc. At present, the mature nano-battery of domestic technology is a nano-activated carbon fiber battery, which is mainly used in electric vehicles, electric motorcycles and electric bicycles. The battery can be charged and cycled 1000 times, and used continuously for about 10 years. Charging takes only about 20 minutes, the flat road travels up to 400km, and the weight is 128kg, which has surpassed the battery level of countries such as the US and Japan. The Ni-MH battery produced by them requires about 6-8 hours of flat road travel for 300km.
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