Views: 0 Author: Site Editor Publish Time: 2022-04-09 Origin: Site
Nickel metal hydride batteries and lithium-ion batteries are widely used in the market. They are pollution-free and environmentally friendly batteries and are an important field of new energy development.
Which is better, nickel metal hydride battery or lithium ion battery?
Difference between lithium ion battery and nickel metal hydride battery Structurally, the positive electrode of Ni MH battery is Ni (OH), the negative electrode is metal hydride, and the electrolyte is 6mol/ L potassium hydroxide solution. Lixo2 + is mixed with lithium ion and graphite ion to form lixo2, while lixo4 + is mixed with lithium ion and ethylene carbonate to form lixo2 + as the cathode of the battery.
Due to its mature technology and good safety, Ni MH battery is an important choice for hybrid electric vehicle (HEV) battery, but it is difficult to meet the demand of higher degree of electrification; At present, lithium Ni MH battery plays a leading role. The important reason is that the battery energy of the existing hybrid electric vehicle is only 1-2kwh, which can not be used purely electric or the battery life of pure electric vehicle is less than 3km.
In the longer term, NiMH can not be applied to PHEV and ev. Mainly because the specific energy and energy density of nickel hydrogen can not meet the requirements of PHEV and ev; The price of raw material Ni (OH) is higher, and the cost of manufacturing high-energy batteries will be higher; The development of Ni MH battery technology is basically mature, and the space for battery performance improvement and cost reduction is very limited. Ni MH battery has the same memory effect as Ni Cd battery, but it is much smaller than Ni Cd battery. Therefore, it is not necessary to discharge every time you charge (because improper operation will damage the battery). You only need to fully charge and discharge once every three months to alleviate the memory effect.
25 ~ 35% (months) for Ni MH battery and 2 ~ 5% (months) for lithium ion battery. The self discharge rate of Ni MH battery is high, while that of lithium-ion battery is very low.
At present, the general capacity of Ni MH battery can reach 2900mah (MAH hour, which is widely known in mainland China as R MAH). After long-term non use, it will leak slightly corrosive and harmful liquid (which will be harmful to human body or damage the device using the battery), and lithium-ion battery has the opportunity to burn or explode when it is not suitable for use. Relatively speaking, Ni MH battery is the safest battery.
The voltage of Ni MH battery is 1.2 V and that of lithium ion battery is 3.7 V. Lithium ion battery has better discharge performance. Ni MH battery has low environmental pollution, mainly some acid-base waste gas, and the most
1. High specific energy and energy density, about twice that of Ni MH battery, which can greatly improve the endurance capacity, higher power, low self discharge and no memory effect of electric vehicles. These characteristics can improve the convenience of electric vehicles;
2. Low cost and price of raw materials;
3. There is much room for technology improvement and cost reduction.
4. Volume: rechargeable lithium-ion battery is widely used in many new mobile devices because it has the advantages of small volume (relatively), light weight, low self discharge rate and no memory effect compared with ordinary nickel cadmium/ nickel hydrogen battery. The batteries of mobile phones, laptops, PDAs and other mobile devices we usually use have been gradually replaced by lithium-ion batteries
The memory effect of Ni MH battery is not very obvious, a little. When in urgent need, it is not necessary to recharge after discharging the light. It is best to recharge after discharging the light in normal use.
5. Power: lithium ion battery has large energy and small battery; The voltage of single lithium-ion battery is three times that of Ni MH battery; Without memory effect, it can be used and charged at any time. It can not be charged at once. In this way, too many times of charging and discharging will affect the service life of the battery. Lithium ion batteries should not be stored for a long time, and part of their capacity will be lost permanently after a long time. It's best to store it in the refrigerator after charging 40%.
6. Charging method: the charging requirements of lithium-ion battery are different from those of nickel cadmium/ nickel hydrogen battery. The single voltage of rechargeable lithium-ion battery is 3.6 V (some battery blocks may have a nominal lithium battery). The voltage and current limiting method is generally adopted for the charging of lithium-ion battery. If a friend wants to charge lithium-ion battery independently, it should be noted that its charging method is different from the constant current charging method adopted by nickel cadmium/ nickel hydrogen battery, and the charger of ordinary nickel cadmium/ nickel hydrogen battery can not be used. Although Ni MH batteries and lithium-ion batteries are different, they are energy batteries in the new era and have played an irreplaceable role in the progress of human life!
According to objective evaluation, when weight becomes a key factor affecting product performance and battery maintenance can be carried out in time, lithium-ion battery is a natural method. When high power, good safety, high reliability and economic practicability are required, NiMH battery will have more advantages.