The positive pole overcharge mainly occurs when the proportion of positive pole materials is too low, which leads to the capacity imbalance between electrodes, resulting in irreversible loss of lithium battery capacity. Moreover, the coexistence and continuous accumulation of oxygen and combustible gas decomposed from positive pole materials and electrolyte may bring potential safety hazards to the use of lithium batteries.

Electrolyte reacts at high voltage

If the charging voltage of the lithium battery is too high, it will lead to the oxidation reaction of the electrolyte and generate some by-products, which will block the electrode micropores and hinder the migration of lithium ions, thus causing the decline of the circulating capacity. The change trend of electrolyte concentration and electrolyte stability is inversely proportional. The higher the electrolyte concentration is, the lower the electrolyte stability is, which affects the capacity of lithium ion battery. During charging, electrolyte will be consumed to some extent. Therefore, it is necessary to supplement during assembly, which will reduce the active materials of the battery and affect the initial capacity of the battery.