Why does the lithium battery capacity decay?

Why do lithium batteries decay? Lithium batteries are the fastest secondary batteries after nickel-cadmium batteries and nickel-hydrogen batteries. Its high-energy characteristics make its future look very bright. However, lithium batteries are not perfect. The biggest problem is the stability of charging and discharging cycles. This article summarizes and analyzes the possible causes of lithium battery capacity degradation, including overcharge, electrolyte differentiation, and self-discharge. Lithium batteries have different intercalation energy between the two electrodes. In order to obtain the best battery performance, the capacity ratio of the two main electrodes should be maintained at a balanced value. In the lithium battery, the capacity balance represents the positive and negative mass ratio, that is: gamma mu003dm+/-u003dΔxC-/ΔyC+ in the C type refers to the ability of the Coulomb theory of the electrode, Δx, yΔ embedded respectively refer to the lithium ion The stoichiometric number of cathode and anode. It can be seen from the above formula that the required mass ratio of the north and south poles depends on the corresponding Coulomb capacity of the north and south poles and the number of reversible lithium ions respectively. In general, a small mass ratio leads to incomplete use of the negative electrode data; a larger mass ratio may be due to overcharge of the negative electrode, which poses a safety hazard. In short, under the best quality ratio, the battery performance is the best. Regarding the air-breathing lithium battery system, its capacity balance does not change during the cycle, and the initial capacity of each cycle is a certain value, but the actual situation is much more complicated. Any secondary use that attacks or consumes lithium ions or electrons may cause a change in the battery capacity balance. Once the battery capacity balance is attacked, this change is irreversible and can be accumulated through multiple cycles, seriously affecting the battery function s attack. In lithium batteries, in addition to the oxidation-reduction reaction during the precipitation of lithium ions, there are also many side reactions, such as the differentiation of electrolyte, the dissolution of active materials, the accumulation of lithium metal, etc. Statement: Some pictures and content of articles published on this site are from On the Internet, if there is any infringement, please contact to delete the previous article: What kind of battery will the next generation of lithium batteries?