After the recent years of elimination, the current power battery market, the mainstream cathode material only left lithium manganate, lithium iron phosphate and ternary lithium three. Each of them has its own strengths and drawbacks. With the development of the market, technological progress and the birth of new materials, upgrading and elimination are still in progress.

The safety, energy density and power density of the cathode material are the basic basis for the current choice of lithium battery type for different models.

1 Basic requirements for cathode materials

The cathode materials that can be widely used must meet the following requirements.

First, the material's own potential is high, so that it can form a large potential difference with the cathode material, resulting in a high energy density core design; at the same time, the charged ions embedded in the electrode potential impact is small, then the charging and discharging process, there will not be excessive voltage fluctuations, and will not bring adverse effects to other electrical system.

Secondly, the material contains high lithium content and the lithium ion embedding and disembedding is reversible. This is a prerequisite for high capacity. Some cathode materials have a very high theoretical capacity, but half of the lithium ions are inactive after the first embedding. Such materials are not commercially viable.

Thirdly, the large diffusion coefficient of lithium ions, the more rapid movement of lithium ions within the material and the strong ability to embed and de-embed. It is a factor that affects the internal resistance of the core and also the power characteristics.

Fourth, the material has a large specific surface area and a large number of lithium embedding locations. With a large surface area, the embedding channel of lithium ions is relatively short, which makes embedding and de-embedding easier. The shallow channels should be accompanied by sufficient lithium embedding sites.

Fifthly, the compatibility with the electrolyte and the thermal stability are good for safety reasons. The cathode material does not react easily with the electrolyte and remains structurally stable at higher temperatures and still does not react easily with the electrolyte. This material does not provide heat for additional heat build-up in the core and reduces the probability of the core entering a self-generated heat phase.

Sixth, the material is easy to obtain and has good processing properties. The low cost, the ease of processing the material into electrodes and the stability of the electrode structure are favourable conditions for the material to be widely used.