The influence of cathode materials on the life of lithium batteries is discussed

Lithium battery cathode materials are one of the important factors that determine the life of lithium batteries. Currently, the commonly used cathode materials in commercial Li-ion batteries are layered lithium cobaltate, spinel lithium manganese oxide, and malachite LFP.However, the problem of rapid volumetric degradation of Li-ion batteries has always been a difficult problem in the research of Li-ion battery life.lithium ion battery VS lead acid battery Many factors can affect the rapid volume decay, which poses a great challenge to the lifetime prediction of Li-ion batteries. If we do not figure out the causes of the volume cliff decay and incorporate these factors into the life prediction model, it will be difficult to do a good job of prediction. Therefore, the importance of combining business and technology is re-emphasized.

Dissolution of transition metals has been a challenge for nearly a decade, even though the cathode materials for lithium-ion batteries are all lithium transition metal oxides. Especially spinel-grade LIMN2O4, the volume usually decays significantly during long-term or high-temperature storage. One of the main reasons is the dissolution of manganese ions. When acid erosion of LIMN2O4 causes an adverse reaction, manganese ions dissolve into the lithium battery electrolyte.

The electrolyte is oxidized and decomposed into hydroxide ions, which are decomposed into hydrochloric acid when the voltage is too high, accelerating the disproportionation reaction of manganese, and the solubility increases with the change of high and low phase difference in the cycle. When manganese ions are dissolved in the electrolyte of a lithium battery, several relative conditions occur, including structural instability, loss of active material, and increased resistance. Lithium ferrous phosphate has a spinel structure that meets the needs of lithium ion de-embedding. However, the manganese in the raw material dissolves in the lithium battery electrolyte at high temperatures, leading to an impairment of the irreversible capability of the lithium battery electrolyte. In addition, the raw material is prone to the Jahn-Teller effect when discharging at high temperatures, which destroys the crystal structure of specific materials and accelerates the battery capacity decay.

LFP is malachite-like structure, has a good stability and safety.lithium battery vs lead acid Diffusion impedance slightly different increase, ohmic impedance and electrochemical corrosion impedance has also been developed to increase, including photoelectrocatalytic impedance can grow to manage the magnitude of the larger impact. The main content of the capacitor loss problem comes from the reaction between the working electrode and the lithium battery electrolyte. Among them, the loss of lithium specificity is the main research cause of capacitor loss.SEI in the process of recycling enterprise due to the change of the volume of the negative electrode and produce a kind of capacitor loss.

Lithium-cobalt oxides are layered structures, which ensure horizontal and cross-variations of the structure during bonding and embedding of lithium ions. Under the conditions of polymer battery charging, the lifetime of lithium batteries is also affected. The increase in charge-discharge ratio will result in the mixing of Li + and Co, which will lead to the transformation of part of LiCoO2 from a hexagonal crystal structure to a cubic crystal structure. With the application of lithium batteries, the content of lithium ions in the electrolyte of lithium batteries gradually decreases, and the capacity of lithium batteries decreases with the decrease in the convective heat exchange capacity of lithium ions. The loss of active lithium ions is mainly caused by the continuous consumption of lithium battery electrolyte reacting with positive and negative level active substances.

With the increase in the number of cycles, the positive electrode impedance increases significantly but the negative electrode impedance changes insignificantly, and the negative electrode capacity decreases significantly but the positive electrode impedance changes insignificantly. Due to the increase of positive electrode interface impedance and the loss of negative electrode capacity, the battery capacity decreases during the cycling process.

Lithium batteries have been widely used in consumer electronic devices for their advantages of high volumetric energy density, high mass energy density, high operating voltage, and low self-discharge rate. With the expansion of the application field of lithium batteries, higher requirements are put forward for their performance. At high temperatures, lithium-ion batteries suffer from fast attenuation, poor low-fold characteristics, and high lifespan, which seriously limit their applications.

By introducing the impact of cathode materials on the life of lithium batteries, we can see that there are many other reasons that affect the life of lithium batteries, such as product quality problems and damage caused by improper use.