Mechanism of the entire overdischarge process and overdischarge-induced internal short circuit in lithium-ion batteries.
Mechanism of the entire overdischarge process and overdischarge-induced internal short circuit in lithium-ion batteries.
复制标题
锂离子电池过放电整个过程及过放电引起内部短路的机理
DOI：
10.1038/srep30248
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发表时间：
2016-07-22
影响因子：
4.6
通讯作者：
Feng X
中科院分区：
文献类型：
--
作者：
Guo R;Lu L;Ouyang M;Feng X
串联连接的锂离子电池容易过放电。过放电导致各种副作用，例如容量退化和内部短路（ISCr）。然而，大多数先前关于电池过放电的研究在电池电压下降到0 V时终止，使得过放电的进一步影响不清楚。本文通过将电池放电至−100%荷电状态（SOC）来研究大型锂离子电池的整个过放电过程。在大约-12%SOC下观察到显著的电压平台，并且在电池通过平台时过放电之后检测到ISCr。扫描电子显微镜（SEM）和X射线衍射（XRD）的结果表明，过放电诱导的ISCr是由电极上的Cu沉积引起的，表明在接近− 12%SOC的电压平台上可能发生Cu集电体溶解。考虑ISCr的预测/机理模型用于评估ISCr的电阻（RISCr），其值在ISCr形成初期急剧下降。通过过放电诱导ISCr是有效的，并且在没有任何机械变形或使用异物的情况下得到良好控制。
Lithium-ion batteries connected in series are prone to be overdischarged. Overdischarge results in various side effects, such as capacity degradation and internal short circuit (ISCr). However, most of previous research on the overdischarge of a cell was terminated when the cell voltage dropped to 0 V, leaving the further impacts of overdischarge unclear. This paper investigates the entire overdischarge process of large-format lithium-ion batteries by discharging the cell to −100% state of charge (SOC). A significant voltage platform is observed at approximately −12% SOC, and ISCr is detected after the cell is overdischarged when passing the platform. The scanning electron microscopy (SEM) and X-ray diffraction (XRD) results indicate that the overdischarge-induced ISCr is caused by Cu deposition on electrodes, suggesting possible Cu collector dissolution at the voltage platform near −12% SOC. A prognostic/mechanistic model considering ISCr is used to evaluate the resistance of ISCr (RISCr), the value of which decreases sharply at the beginning of ISCr formation. Inducing the ISCr by overdischarge is effective and well controlled without any mechanical deformation or the use of a foreign substance.