关键词: 锂离子电池, N/P比设计, 高温存储, 循环性能, 电极电位

Abstract:

In this research, a pouch lithium-ion battery was fabricated using Li(Ni_0.8Co_0.1Mn_0.1)O₂ as cathode material and synthetic graphite as anode material. Three different N/P ratios were designed by changing the capacity of the anode. The cell initial capacity, first discharge efficiency, initial internal resistance, rate discharge, high and low temperature discharge, high-temperature storage, and cycling performance were investigated, and the findings indicate that increasing the N/P ratio can improve the battery's initial discharge capacity. However, increasing the N/P ratio will increase the potential of the positive electrode, and the electrolyte will be easily oxidized on the positive electrode side. The low N/P ratio may ensure that the positive electrode has a lower electrode potential, reducing side effects and improving high-temperature storage and cycling performance. However, the N/P ratio is substantially smaller, and Li⁺ is easily lowered, resulting in a loss of active lithium.

Key words: lithium ion battery, N/P ratio, high temperature storage, cycling performance, electrode potential