The charging and discharging process of lithium-ion batteries includes the transmission of lithium ions in three materials: graphite negative electrode particles, electrolyte, and positive electrode materials. Although the particle size of positive and negative electrode materials is generally between 5 and 15 jam, which reduces the diffusion length of lithium ions in the 1 phase, the solid-phase diffusion coefficient of lithium ions in electrode materials is very small. For example, the diffusion coefficient of graphite negative electrode materials is about 10cm2/s, and the diffusion coefficient of spinel LiMnO positive electrode materials is about 10ClTI/s. The in-phase diffusion of lithium ions in electrode materials will affect the discharge behavior of the battery. Under low temperature conditions, the decrease in the discharge level of the battery indicates an increase in the polarization of the inner and outer layers of the positive and negative electrode particles, that is, an increase in the transmission impedance of the lithium ion storage positive and negative electrode solid particle leaf 1, which leads to the premature reaching of the discharge termination voltage during the discharge process, and the corresponding decrease in discharge capacity. Huangl7l et al. found through their research that the insertion/extraction process of lithium ions is asymmetric under low temperature conditions. For fully charged graphite electrodes, it is relatively easy to release embedded lithium ions below -20 ℃. However, at the same temperature, embedding lithium ions into fully discharged graphite electrodes encounters serious obstacles. The author believes that the asymmetric process is caused by the diffusion of lithium ions inside graphite. By reducing the particle size of the electrode material, the low-temperature performance of the battery has been significantly improved.

Read recommendations:

7/AAA USB 1.5V 600mWh

Characteristics of lithium-ion batteries.401030 battery

Want to know where is the advantage of ternary lithium batteries?solar energy storage lithium ion ba

solar energy storage battery pack

Nickel Hydride No. 5 battery