Battery is a general term for batteries, which is a widely used name among the people, but lithium-ion batteries, nickel-metal hydride batteries, nickel-cadmium batteries, lead-acid batteries, etc. can all be called batteries. The following is an introduction to the types of batteries that have been put into industrial applications on the market.
The battery is the power source of the electric vehicle. At present, the key factor restricting the development of electric vehicles is the unsatisfactory power animal battery. The important performance indicators of electric vehicle batteries are specific energy, specific power and service life. To make electric vehicles compete with internal combustion engine vehicles, the key is to develop batteries with high specific energy, high specific power, long service life and low cost.
- Lead-acid battery
Lead-acid batteries have a history of more than 100 years and are widely used as starting power sources for internal combustion engine vehicles.
It is also a mature battery for electric vehicles. It has good reliability, readily available raw materials and low price; its specific power can basically meet the power requirements of electric vehicles. But it has two major disadvantages; one is low specific energy, occupies too much mass and volume, and has a short mileage on a single charge; the other is short service life and high cost of use.
- Nickel-cadmium battery
The application of nickel-cadmium batteries is second only to lead-acid batteries, and its specific energy can reach 55W/kg, and its specific power exceeds 190W/kg. It can be quickly charged and has a long cycle life, which is more than twice that of lead-acid batteries, and can reach more than 2,000 times, but the price is 4 to 5 times that of lead-acid batteries. Although its initial acquisition cost is high, its long-term actual use cost is not high due to its advantages in energy and service life. The disadvantage is that there is a "memory effect", which is easy to reduce the available capacity of the battery due to poor charging and discharging. It must be fully charged and discharged after about ten times of use. If there is a "memory effect", it should be continuously charged and discharged for 3 to 5 times to release the memory. In addition, cadmium is toxic, so attention should be paid to recycling it in use to avoid environmental pollution caused by cadmium.
- Sodium-sulfur battery
The advantages of sodium-sulfur batteries: one is high specific energy. Its theoretical specific energy is 760W/kg, which is actually more than 100W/kg, which is 3 to 4 times that of lead-acid batteries; the other is that it can discharge with high current and high power. Its discharge current density can generally reach 200~300mA/mm2, and it can release 3 times its inherent energy in an instant; another is high charge and discharge efficiency. Since the solid electrolyte is used, there is no self-discharge and side reactions commonly used in liquid electrolyte secondary batteries, and the current efficiency of charge and discharge is almost 100%. The disadvantage of sodium-sulfur battery is that its working temperature is 300~350℃. Therefore, the battery must be heated and kept warm during operation. The high temperature corrosion is serious, and the battery life is short. Now there are high-performance vacuum insulation technology, which can effectively solve this problem. There are also problems such as performance stability and use security that are not ideal. In the 1980s and 1990s, foreign countries focused on the development of sodium-sulfur batteries as applications in fixed occasions (such as power station energy storage), and more and more showed their superiority. In this regard, Japanese companies have made the most significant progress. As a generally optimistic electric vehicle battery in the near future, it has been listed as a medium-term development electric vehicle battery by the United States Advanced Battery Consortium (USMABC). ; The specific energy reaches 109W/kg, the cycle life is 1200 times, and the best one has traveled 2300km without failure during the loading test.
- NiMH battery
Nickel-metal hydride batteries are alkaline batteries. Nickel-metal hydride batteries have a long cycle life and no memory effect, but they are expensive. Although its initial acquisition cost is high, its long-term actual use cost is not high due to its advantages in energy and service life. At present, foreign companies producing nickel-metal hydride batteries for electric vehicles currently have two types of unit cells, 80A and 130A, with a specific energy of 75-80W/kg and a cycle life of more than 600 times. This kind of battery is installed on several electric vehicles for trial use. One type of vehicle can travel 345km on a single charge, and one vehicle can travel more than 80,000 kilometers in one year. Due to the high price, mass production is not yet available. Domestically, 55A and 100A unit cells have been developed, with a specific energy of 65W/kg and a power density of more than 800W/kg of nickel-metal hydride batteries.
- Lithium-ion battery
Lithium-ion secondary batteries, as new high-voltage, high-energy-density rechargeable batteries, have a wide range of prospects for civilian and special applications due to their unique physical and electrochemical properties. Its outstanding features are: light weight, large energy storage, no pollution, no memory effect, and long service life. In the case of the same volume and weight, the storage capacity of lithium-ion batteries is 1.6 times that of nickel-hydrogen batteries and 4 times that of nickel-cadmium batteries. At present, human beings have only developed and utilized 20% to 30% of their theoretical power, so the development prospects are very high. bright. At the same time, it is a real green battery that will not pollute the environment, and is currently the best battery that can be applied to electric vehicles. my country began to develop and utilize lithium-ion batteries in the 1990s, and has made breakthroughs so far, developing lithium-ion batteries with completely independent intellectual property rights.
- Flywheel battery
The flywheel battery is a new concept battery proposed in the 1990s. It breaks through the limitations of chemical batteries and uses physical methods to achieve energy storage. When the flywheel rotates at a certain angular velocity, it has a certain amount of kinetic energy. The flywheel battery converts its kinetic energy into electrical energy. A high-tech flywheel is used to store electrical energy, much like a standard battery. There is a motor in the flywheel battery. When charging, the motor runs as a motor. Driven by an external power supply, the motor drives the flywheel to rotate at a high speed, that is, "charging" the flywheel battery with electricity increases the speed of the flywheel to increase its function; discharge When the motor is in the state of generator, it outputs electric energy to the outside driven by the flywheel to complete the conversion of mechanical energy (kinetic energy) to electric energy. When the flywheel battery is powered, the speed of the flywheel gradually decreases. The flywheel of the flywheel battery runs in a vacuum environment with a very high speed (200000r/min), and the bearings used are non-contact magnetic bearings. It is said that the specific energy of the flywheel battery can reach 150W/kg, the specific power can reach 5000~10000W/kg, the service life can be as long as 25 years, and the electric vehicle can travel 5 million kilometers.
- Nickel-zinc battery
The new sealed nickel-zinc battery has the advantages of high performance, high power and high current discharge. This advantage enables nickel-zinc batteries to meet the energy needs of electric vehicles for trips, climbing and acceleration on a single charge. Nickel-zinc battery is a product developed and produced by the National Energy Research Corporation (ERC) of the United States, and Xiamen Battery Factory has cooperated with it to introduce this product. Nickel-zinc batteries are very competitive batteries. Its advantages are that its specific energy reaches more than 50Wh/k, and its volume energy has exceeded that of nickel-cadmium batteries and is smaller than that of nickel-hydrogen batteries. High current discharge, the voltage of the battery will be balanced in a wide range, and has a long service life, cycle life ≥ 500 times. Charging time ≤ 3.5h, fast charging ≤ 1h. In particular, it is worth mentioning that the self-discharge resistance to charge attenuation is very good. At room temperature for one month, the self-discharge is less than 30% of the rated charge. At a high temperature of 50°C, when the battery is discharged at C/3, the battery charge decays ≤10% of the rated charge, while at 15°C, the C/3 discharge is ≤30%. Nickel-zinc batteries and lead-acid batteries have good compatibility in appearance, and all vehicles that use lead-acid batteries can be replaced with nickel-zinc batteries. Judging from the current price, nickel and zinc are still slightly more expensive, but it is believed that the price will naturally drop after its application volume increases. Compatibility with the outline of lead-acid batteries makes nickel-zinc batteries more convenient to replace lead-acid batteries and become an ideal power source for electric vehicles.
- Zinc-air battery
Zinc-air battery, also known as zinc-oxygen battery, is a kind of metal-air battery. The theoretical value of the specific energy of the zinc-air battery is 1350W/kg, and the current specific energy has reached 230Wh/kg, which is almost 8 times that of the lead-acid battery.
It can be seen that the development space of zinc-air battery is very large. The zinc-air battery can only be operated by replacing the zinc electrode.
"Mechanical charging". The time to replace the electrode can be completed within 3 minutes. Put on a new zinc electrode, "charge"
Very short time, very convenient. The development of such a battery eliminates the need for the construction of social security facilities such as charging stations. Zinc electrodes can be purchased in supermarkets, battery operating points, auto parts stores, etc., which is very beneficial to popularizing this battery electric vehicle. The battery has the advantages of small size, large charge capacity, small mass, normal operation in a wide temperature range, no corrosion, safe and reliable operation, and low cost. At present, the charge capacity of the test battery is only five times that of the lead-acid battery, which is not ideal. However, the charge of 5 times that of lead-acid batteries has attracted the attention of the world. The United States, Mexico, Singapore and some European countries have tried them on postal cars, buses and motorcycles. It is also a very promising electric vehicle. Battery.