Understanding capacity fade in silicon based electrodes for lithium-ion batteries using three electrode cells and upper cut-off voltage studies
Understanding capacity fade in silicon based electrodes for lithium-ion batteries using three electrode cells and upper cut-off voltage studies
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DOI：
10.1016/j.jpowsour.2015.10.066
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发表时间：
2016-01-20
影响因子：
9.2
通讯作者：
Dashwood, Richard
中科院分区：
文献类型：
--
作者：
Beattie, Shane D.;Loveridge, M. J.;Dashwood, Richard
商用锂离子电池通常在3.0 V和4.2 V之间循环。这些电压限制是基于阴极（例如锂钴氧化物）和阳极（例如石墨）的特性来选择的。当研究交替的阳极/阴极化学时，经常错误地使用相同的截止电压。硅（Si）基阳极作为锂离子电池石墨的高容量替代品被广泛研究。当硅基阳极与高容量阴极（例如锂镍钴铝氧化物; NCA）配对时，电池通常遭受快速容量衰减。本文的目的是了解上限截止电压的选择如何影响Si/NCA电池的性能。对三电极电池数据的仔细研究将表明，Si/NCA电池中的容量衰减是由于不断演变的硅电压分布，其将阴极处的上限电压推到> 4.4V（相对于Li/Li+）。由于新锂的释放，这种行为最初提高了循环效率，但最终降低了循环效率，导致容量快速衰减。(C)2015年，作者。由爱思唯尔公司出版。这是一篇开放获取的文章，使用CC BY许可证（http：//creativecommons.org/licenses/by/4.0/）。
Commercial Li-ion batteries are typically cycled between 3.0 and 4.2 V. These voltages limits are chosen based on the characteristics of the cathode (e.g. lithium cobalt oxide) and anode (e.g. graphite). When alternative anode/cathode chemistries are studied the same cut-off voltages are often, mistakenly, used. Silicon (Si) based anodes are widely studied as a high capacity alternative to graphite for Lithium-ion batteries. When silicon-based anodes are paired with high capacity cathodes (e.g. Lithium Nickel Cobalt Aluminium Oxide; NCA) the cell typically suffers from rapid capacity fade. The purpose of this communication is to understand how the choice of upper cut-off voltage affects cell performance in Si/NCA cells. A careful study of three-electrode cell data will show that capacity fade in Si/NCA cells is due to an ever-evolving silicon voltage profile that pushes the upper voltage at the cathode to >4.4 V (vs. Li/Li+). This behaviour initially improves cycle efficiency, due to liberation of new lithium, but ultimately reduces cycling efficiency, resulting in rapid capacity fade. (C) 2015 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).