Why is the lithium battery inside soft?

A "lithium battery" is a type of battery using a lithium metal or a lithium alloy as a negative electrode material and using a nonaqueous electrolyte solution. Lithium metal batteries were first proposed and studied by Gilbert N. Lewis in 1912. In the 1970s, M.S.WhitTIngham proposed and began researching lithium-ion batteries. Due to the very active chemical properties of lithium metal, the processing, storage and use of lithium metal are very demanding on the environment. Therefore, lithium batteries have not been used for a long time. With the development of science and technology, lithium batteries have become the mainstream.

Lithium-ion batteries are an alternative to metal lithium batteries that have appeared in the past few years. The main components of the batteries are positive and negative electrodes, electrolytes, separators and outer casings.

The positive electrode--- uses a carbon electrode capable of absorbing lithium ions. When discharging, lithium turns into lithium ion and leaves the anode of the battery to reach the cathode of the lithium ion battery.

The negative electrode----material selects an intercalable lithium compound whose potential is as close as possible to the lithium potential. For example, various carbon materials include natural graphite, synthetic graphite, carbon fiber, mesophase carbon, and the like, and metal oxides.

Electrolyte---a mixed solvent system of an alkyl carbonate such as ethylene carbonate, propylene carbonate and low viscosity diethyl carbonate of LiPF6.

Diaphragm---Polyene microporous membranes such as PE, PP or their composite membranes, especially PP/PE/PP three-layer membranes have low melting point and high puncture strength, which plays a role in heat insurance.

Enclosure---With steel or aluminum material, the cover assembly has the function of explosion-proof and power-off.

Lithium batteries can be roughly divided into two categories: lithium metal batteries and lithium ion batteries. Lithium-ion batteries do not contain metallic lithium and are rechargeable. The fifth-generation lithium-metal battery of rechargeable batteries was born in 1996, and its safety, specific capacity, self-discharge rate and performance price ratio are better than lithium-ion batteries. Due to its own high technical requirements, only a few companies in the country are producing such lithium metal batteries.

The soft-pack lithium battery is simply a liquid lithium-ion battery with a polymer shell. The structure is packaged in aluminum plastic film, and in the case of a safety hazard, the soft pack battery will only burst at most.

Good safety performance

The soft pack battery does not explode like a steel shell aluminum shell.

Light weight

The weight of the soft pack battery is 40% lighter than the equivalent capacity of the steel shell lithium battery, which is 20% lighter than the aluminum shell battery.

Large capacity

The soft pack battery has a capacity of 10 to 15% higher than the steel shell battery of the same size, and is 5 to 10% higher than the aluminum shell battery.

Small internal resistance

The internal resistance of the soft pack battery is smaller than that of the lithium battery. At present, the internal resistance of the domestic soft pack battery core can be as low as 35 mΩ, which greatly reduces the self-consumption of the battery.

Flexible design

The shape of the soft pack battery can be customized according to the customer's needs, and a new battery model can be developed.

The existing soft pack battery core models are few and cannot meet the market demand;

Developing new models is costly.

There are two types of lithium batteries, lithium batteries and lithium polymer batteries.

The inside of a common lithium battery is a liquid electrolyte, which must be wrapped with a hard outer casing to achieve structural stability and safety.

Lithium polymer batteries are solid electrolytes. Of course, it's not very hard (it can be done very hard). The shape can be changed arbitrarily to suit different needs.

The advantages of the soft-pack lithium battery are good safety performance, light weight, large capacity, small internal resistance and flexible design.

The material of the lithium battery case, if it is packaged outside, it is not easy to see, you must see the battery body, the weight of the steel case battery will be more important than the same volume of the battery, but the aluminum case and the flexible package are not easy to distinguish, but The flexible packaging battery will be softer than the aluminum battery, and it will be easily deformed by hand.

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