商用Li_4Ti_5O_(12)电池的温度特性及容量衰减模型

Temperature Characteristics and Capacity Fading Model of Commercial Li_4Ti_5O_(12) Batteries

钛酸锂(Li_4Ti_5O_(12),LTO)由于具有诸多优点,如超长的循环寿命、优异的倍率循环性能和良好的安全性,被认为是最具潜力的负极材料,有望在储能领域大规模应用。该文通过测试商用软包NCM/LTO基锂离子电池(标称容量10A?h,额定电压2.2~3.5V)在不同温度下5400次循环的容量衰减,获得循环放电容量曲线。通过对其进行特定循环周数的节点测试,获得电池在不同温度下的0.1C放电容量,分离电池的不可逆容量损失,利用阿仑尼乌斯公式建立容量衰减模型,并拟合曲线,公式很好地符合了不同温度的衰减情况,并得到在温度T与循环时间tn下的容量预测经验公式,分别对2500、5000、7500和10000h不同温度下的容量进行预测。

Lithium titanate （Li4TisO12, LTO） is considered to be the most promising anode material due to its many advantages, such as long cycle life, excellent rate performance and safety. The battery based on LTO as the anode is expected to be applied for large-scale energy storage. The capacity fading data were obtained by cycling a commercial soft package Li（Ni-Co-Mn）O2/LTO-based lithium ion batteries with nominal capacity of 10A.h and nominal voltage of 2.2-3.5V in different temperatures. A node capacity test （0.1C rate test after every 600 cycles） was used to separate the irreversible capacity loss from temperatures effects. The capacity decay model was established by using the Arrhenius formula and associated curve fitting. The formula is consistent with the different temperature attenuations. The empirical formula for predicting the capacity under temperature T and cycle time tn was obtained and the capacities at different temperatures for 2500, 5000, 7500 and 10000.hours were predicted.