Amorphous Structure Analysis of Si Anode for Li Ion Battery
Amorphous Structure Analysis of Si Anode for Li Ion Battery
复制标题
DOI：
10.1017/s1431927618008115
复制
发表时间：
2018-08
影响因子：
2.8
通讯作者：
Y. Shimo;A. Hirata;H. Yamasaki;Hiroyuki Yamaguchi;Kazuaki Sato
中科院分区：
文献类型：
--
作者：
Y. Shimo;A. Hirata;H. Yamasaki;Hiroyuki Yamaguchi;Kazuaki Sato
锂离子电池（lib）是便携式电子设备、混合动力/插电式混合动力汽车（HV/PHV）和电动汽车（EV）的主要储能设备。特别是在高压/PHV和EV中的应用，预计lib的重量和体积能量密度将比目前的lib高得多。硅作为锂离子电池的替代阳极是一种有吸引力的材料，因为它的理论容量比目前的碳（石墨）阳极大十倍以上，所以含硅锂离子电池的阳极一直是最近研究的主题。然而，硅作为锂离子电池阳极存在一些问题。其中一个问题是“滞后性”；放电状态下的电池电压（开路电压；OCV）曲线与充电状态相比降低。虽然迟滞导致锂离子电池性能下降，但其发生的原因尚不清楚。最近，一项关于电压迟滞宏观分析的研究报道了Si阳极的机械应力可能与迟滞[2]有关。然而，对硅阳极锂离子电池的磁滞现象进行微观分析的研究尚未见报道。因此，在这项工作中，我们旨在研究滞后的微观机制。
Lithium-ion batteries (LIBs) are major energy storage in portable electronic devices, hybrid/plug-in hybrid vehicles (HV/PHV), and electric vehicles (EV). Especially, with regard to the use in HV/PHV and EV, LIBs are expected to have much higher gravimetric and volumetric energy densities than current LIBs. Silicon is an attractive material as an alternative anode of LIB because its theoretical capacity is more than tenfold greater than the current carbon (graphite) anode, so LIBs containing Si anode have been the subject of much recent investigation [1]. However, Si has some problems to be used as LIB anode. One of the problems is “hysteresis”; cell voltage (Open Circuit Voltage; OCV) profiles at the discharging state decrease compared with the charging state. Although hysteresis leads to declining the performance of LIB, the reason why it occurs has been poorly understood. Recently, a study was conducted on macroscopic analysis of voltage hysteresis and it was reported that the mechanical stress of Si anode might have relation to hysteresis [2]. However, no study has been reported on the microscopic analysis to investigate hysteresis of Si anode LIB. Therefore, in this work, we aimed to study the microscopic mechanism of hysteresis.