Safety performance and application analysis of lithium cobalt oxide battery

We explain in detail by comparing the safety of four types of batteries: lithium nickel cobalt manganate, lithium iron phosphate, lithium cobaltate and lithium manganate:

1, nickel cobalt manganese oxide lithium (ternary) battery

In the actual available theoretical energy has been greatly improved, in terms of lithium cobalt acid battery, can better play a high-capacity use, but from the material point of view, terpolymer battery with nickel-cobalt manganese oxide lithium and organic electrolyte, has not fundamentally solved the safety problem, when the battery short-circuit will appear too much current, resulting in safety risks.

The theoretical capacity is 170mAh/g and the actual capacity of the material is 160mAh/g. In terms of safety, Lithium Iron Phosphate Battery has high thermal stability and low electrolytic liquid oxygenation capacity, so it has high safety; however, the defects are low conductivity, large volume, large amount of electrolyte, and poor consistency of the battery due to large capacity.

3, lithium cobalt acid battery

The biggest feature in the preparation is that after being fully charged, there are still a large number of lithium ions left in the positive electrode, that is to say, more lithium ions attached to the positive electrode can not be accommodated on the negative electrode, but in the overcharged state, the excess lithium ions on the positive electrode will still swim to the negative electrode, because it can not be fully accommodated back to the formation of lithium metal on the negative electrode, because lithium metal is a dendritic crystal, Therefore, they are called dendrites, and once dendrites form, they will provide an opportunity to Pierce the diaphragm, which will form an internal short circuit. Because the important component of the electrolyte is carbonate, the flash point and boiling point are low, and it will burn or even explode at higher temperatures. Controlling the formation of lithium dendrites is relatively easy on small-capacity lithium-ion batteries, so lithium-cobalt acid batteries are currently limited to small-capacity batteries such as portable electronic devices and cannot be used for power Lithium Batteries.

4, manganese acid Lithium Battery

The material of the lithium manganese acid battery has a certain point that can ensure that in a fully charged state, the positive lithium ions can be fully embedded in the negative carbon hole, rather than having a certain residue in the positive electrode like lithium cobalt acid, If the manganate lithium-ion battery is subjected to a strong external force or if the preparation process is cut short, this can cause the battery to form a rapid movement of lithium ions during the charge and discharge cycle. Dendrites are formed when the negative electrode does not have time to fully receive the lithium ions. This is prevented by testing the battery at the factory. In short, the test qualified lithium manganese acid battery generally does not occur safety accidents, lithium manganese acid stable structure makes its oxidation performance is far lower than lithium cobalt acid, even if the external short circuit, it can basically prevent the combustion and explosion caused by the precipitation of lithium metal.

Application of Lithium Cobalt Acid Battery

After long-term development, lithium cobalt acid batteries have formed four product lines: cylindrical batteries, polymer soft pack batteries, aluminium shell batteries and steel shell batteries, which are used in high-end, mid-end and low-end markets.

1, the high-end application of lithium cobalt acid battery is important for notebook computers, because notebook computers have high requirements for battery capacity and safety, so at present, only cylindrical lithium cobalt acid battery with good consistency can meet the application. At present, the cylindrical lithium-ion battery manufacturers that can be accepted by the international brand manufacturers of notebook computers are only SONY, Sanyo, Samsung and LG, although many domestic manufacturers can also produce cylindrical lithium-ion batteries in the past two years, but it is difficult to enter the international first-line factories.

2, the mid-end customers of lithium cobalt acid battery are major first-line brand mobile phones, digital cameras, mobile DVD, first-line brand Mp4, GpS and digital photo frame manufacturers. The domestic four lithium battery giants and other large-scale manufacturers of lithium-ion battery sales are mainly concentrated in this area. The same is the mobile phone, Mp4 and digital photo frame, the quality requirements of the first-line brand lithium-ion battery will be much stricter, but at the same time, the profits of the first-line brand customers will be relatively high, the payment will be more on time, and this part of the customers pay more attention to the strength of the battery company and the quality of the battery. The mid-market demand for lithium-ion cobaltate batteries is important for soft-pack batteries and aluminium-shell batteries.

3, the low-end customers of lithium cobalt acid battery is important to foreign trade business based Mp3, Mp4, GpS, digital photo frame manufacturers and domestic second- and third-line mobile phone manufacturers and Shanshan mobile phones, these manufacturers are mainly concentrated in the Pearl River Delta, the main demand is steel shell battery, but also some aluminium shell and liquid soft pack battery demand. Second and third tier mobile phone manufacturers and cottage mobile phone manufacturers are mostly domestic trade, price is the most important competitive factor of their products; Other Mp3 manufacturers are based on foreign trade business, because they are at the lower end of their industrial chain, so the price is often a factor they value very much. This price-driven customer group is the target customer of the two to three hundred small and medium-sized lithium-ion battery cell factories or pACK factories scattered across the Pearl River Delta. This part of the low-end customers often only heavy price not heavy quality, and many companies are not good business reputation, which leads to the low-end market battery suppliers not only low profits, but also high risk, fierce competition.