Too much negative electrode will consume the lithium in the positive electrode. Therefore, generally speaking, the graphite negative electrode in custom lithium battery pack will have slightly more than the positive electrode, but not too much. If there are too many positive electrodes, excess lithium ions from the positive electrode cannot enter the negative electrode during charging, and lithium will be deposited on the surface of the negative electrode, leading to the formation of dendrites, thus affecting the cycle performance of the battery. In this case, the battery capacity is limited by the capacity of the positive electrode, and the ratio of negative electrode capacity/positive electrode capacity is greater than 1.0 (i.e. For traditional graphite negative electrode lithium-ion batteries, the main shortcomings of battery charge and discharge cycle failure mainly occur in lithium deposition and dead zone problems on the negative electrode side, so the solution of excess negative electrode is usually used. When designing custom lithium battery pack, it is very important to correctly calculate the reasonable ratio of positive and negative electrode capacities.

Lithium battery anode and cathode