Stress-limited fast charging methods with time-varying current in lithium-ion batteries
Stress-limited fast charging methods with time-varying current in lithium-ion batteries
复制标题
锂离子电池时变电流应力限制快速充电方法
DOI：
10.1016/j.electacta.2018.09.009
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发表时间：
2018
影响因子：
6.6
通讯作者：
Junqian Zhang
中科院分区：
文献类型：
--
作者：
Bo Lu;Yanfei Zhao;Yicheng Song;Junqian Zhang
本文阐述了时变电流快速充电方法的优点。推导了一般时变电流充电过程的浓度和应力的解析解。首先评估了一种用于逐渐减小值的多级恒流的快速充电协议。正确设计的多级恒流方法能够同时抑制应力溢出和加速充电，但级间急剧切换引起的应力波动是不可避免的。然后研究了具有非线性指数电流的充电方案。施加的电流随时间连续、平滑地变化，因此避免了应力波动。提出了指数电流方法设计的建议，以在不牺牲充电容量或增加机械故障风险的情况下实现最佳充电加速。精心设计的指数电流法在加速充电速度方面优于多级恒流法。
This article sheds light on advantages of fast charging methods with time-varying current. Analytical.solutions of concentration and stress for charging processes with general time-varying currents are.derived. A fast charging protocol for a multistage constant current of gradually decreasing value is first.evaluated. A properly designed multistage constant-current method is able to simultaneously suppress.stress overflow and accelerate charging, but stress undulation induced by sharp switching between.stages is inevitable. A charging scheme with a nonlinear exponential current is then investigated. The.applied current varies continuously and smoothly with time so stress undulation is avoided. Suggestions.for the design of an exponential current method are proposed to achieve the best charging acceleration.without sacrificing charging capacity or increasing risk of mechanical failures. A well-designed exponential-.current method is superior to a multistage constant-current method in accelerating charging.speed.