What is the memory effect of the battery?

We all have this experience. After using lithium battery for a period of time, the durability of the battery gradually becomes weaker. What's the matter? That is the memory effect of lithium battery. What is the memory effect of battery?

Effect diagram of lithium battery crystallization

The memory effect principle of the battery is crystallization, and this reaction will hardly occur in the lithium battery. For the new battery, the grain size of the electrode material is only 1 micron in diameter. The maximum electrode surface area can be obtained


After crystallization, the grain size increases, and its grain diameter can reach 100 microns, which greatly reduces the available electrode area. Moreover, the grown grain may cause self-discharge to increase, and the electrode diaphragm is punctured by the crystal, resulting in micro-circuit. This will reduce the capacity of the battery and damage its performance. The capacity of the lithium-ion battery will still decline after many times of charging and discharging, and the reasons are complex and diverse. It is mainly the change of the positive and negative electrode material itself. From the molecular level, the hole structure containing lithium ion on the positive and negative electrode will gradually collapse and block; From the chemical point of view, it is the active passivation of the positive and negative electrode materials, and the side reaction occurs to generate stable other compounds. Physically, the positive electrode material will gradually peel off, which ultimately reduces the number of lithium ions in the battery that can move freely during charging and discharging.