1. Decrypt why lithium batteries lose their temper

First of all, we must understand the composition of lithium batteries. Lithium batteries currently on the market are composed of four parts: positive electrode material, negative electrode material, electrolyte, separator and binder material.

In the field of electric vehicle travel, Tesla must be mentioned in terms of lithium batteries. As the industry’s indicator, the Tesla Model 3’s lithium iron phosphate battery appeared in the 333th “Product Notice” issued by the Ministry of Industry and Information Technology, causing a major earthquake in the field of lithium battery materials. The primary lithium is converted to lithium iron phosphate.

In our electric two-wheeler industry, when it comes to lithium batteries for electric vehicles, what do we first think of? I believe most people’s answer is: it will explode!

2. The mystery of lithium battery material selection

First of all, we must understand the composition of lithium batteries. Today, lithium batteries on the market are composed of four parts: positive electrode material, negative electrode material, electrolyte, separator and binder material.

The reason for the thermal tempering of lithium batteries lies in the positive electrode material of lithium batteries: Li is very active. Once affected by external force, it is easy to derail, causing short circuit between the positive and negative electrodes, and then the battery heats up and catches fire, and then we see that the time from the short circuit to the ignition process is very short, usually only a few minutes.

At present, the industry has two methods to prevent short circuits: one is to improve the performance of the internal separator of the lithium battery so that the positive electrode and the negative electrode do not easily deviate, and the other is to use a relatively mild lithium battery. Cathode material for ion battery. The article with specific material will be described below. Mentioned.

In the development and production of lithium batteries, the choice of cathode material is the key. After years of market verification, the current mainstream cathode materials are only lithium iron phosphate, ternary lithium and lithium manganate. Each of them has its own advantages and disadvantages.

Lithium iron phosphate battery: refers to a lithium battery using lithium iron phosphate as the positive electrode material. The advantage is that it is relatively stable, safe and reusable, but has low energy density. In order to meet the same cruising range, lithium iron phosphate is larger and heavier, but the price is lower. This is why the price of Tesla’s lithium iron phosphate version will be reduced. This is also a must for the future lithium battery electric two-wheeled vehicle cathode material.

Ternary lithium battery: refers to a lithium battery in which three materials of nickel, cobalt and manganese are mixed and matched in a certain proportion as the positive electrode material. The advantage is high energy density, but the bigger disadvantage is poor safety.

Lithium manganate battery: refers to a battery that uses lithium manganate material as the positive electrode. The battery has medium energy density, average lifespan, average cycle performance, acceptable high and low temperature and reasonable price. It is a relatively medium material.

3. How to choose a safer lithium battery

At present, the basic requirement for lithium batteries in the electric two-wheeler industry is safety. In the new era of my country’s standard for electric vehicles, choosing safe lithium batteries is also the focus of dealers’ work.

Industry professionals believe that only high-capacity, multi-lifecycle, long-term market-proven lithium batteries are safe and reliable. When choosing a lithium battery, not only the production process, the PACK process, whether there is a BMS, whether the shell and component design are waterproof, drop-proof, and anti-extrusion, but also need to be checked. For sample inspection reports, attention should also be paid to consistency and mass production safety.