摘要
放电倍率与可用容量关系通常采用Peukert方程来描述,但Peukert方程存在不能区分电流倍率对于电荷损耗及剩余容量影响的问题。为探讨Peukert方程背后起主导作用的机理并建立合理的方程,该文以采用二阶段恒流放电试验,分别建立Peukert形式的方程。其中,第一阶段可用容量的方程(PE1)即原始Peukert模型,剩余容量的Peukert形式方程(PE2)反映了电流对于浓度梯度和扩散的影响。最大可用容量Peukert方程(PE3)反映了电流倍率与电荷损耗的关系。此外,磷酸铁锂电池(LFP)最大可用容量与倍率在对数域的曲线存在分叉、非线性现象,反映了可用容量、内阻等内在特性受温度、电流影响而增大或波动的特点。其Peukert系数(1.01～1.06)远小于镍镉、铅酸电池,说明其电量损失及大电流影响较小。
The Peukert equation relates the C-rate and the available capacity at the given discharge rate, but conifuses the two mechanisms of the charge loss in the discharge process and the residual capacity at the end of the discharge process. A two-stage constant current discharge test of a lithium iron phosphate （LFP） battery was used to analyze the discharge process with the Peukert and similar equations used to describe the dominant principles and separate the influences of the two mechanisms. The Peukert equation for the first stage available capacity （PE1） is the original Peukert equation, while the Peukert equation for the second stage available capacity （residual capacity） （PE2） relates the C-rate and the residual capacity. The Peukert equation for the maximum available capacity （the sum of the two stages） （PE3） relates the C-rate and the charge loss. The diffusion and nonlinear phenomena in the logistic curve for the maximum available capacity of the LFP batteries and the C-rate are in accordance with the current and temperature effects on solid electrolyte interphase （SEI） layers and diffusion, and consequently with the available capacity, internal resistance, and potential. The Peukert coefficient for the LFP battery varies between 1.01 -1.06, which is very small compared to lead-acid and NiMH batteries, indicating its small charge loss and the small influence of C-rate on the losses.
出处
《清华大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2010年第2期295-298,共4页
Journal of Tsinghua University(Science and Technology)
基金
中国博士后科学基金资助项目(20070410520)
汽车安全与节能国家重点实验室开放基金资助项目(KF09011)
关键词
磷酸铁锂电池
Peukert模型
二阶段放电
剩余电量
荷电状态
lithium ron phosphate battery
Peukert equation two-stage discharge
remaining capacity
state of charge （ SOC ）
