The Effect of Mechanical Strain on Lithium Staging in Graphene
The Effect of Mechanical Strain on Lithium Staging in Graphene
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DOI：
10.1002/aelm.202000981
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发表时间：
2020-08
影响因子：
6.2
通讯作者：
Joshua V. Pondick;Sajad Yazdani;Milad Yarali;Serrae N. Reed;D. Hynek;J. Cha
中科院分区：
文献类型：
--
作者：
Joshua V. Pondick;Sajad Yazdani;Milad Yarali;Serrae N. Reed;D. Hynek;J. Cha
开发下一代金属离子电池电极需要了解纳米材料的嵌入动力学。在此，它表明，微尺度的机械应变显着影响有序锂相在石墨烯中的形成。在锂嵌入期间在边缘处机械约束的石墨烯微片的原位拉曼光谱揭示了诱导锂分级的电化学势的高达1.26 V的厚度依赖性增加。虽然诱导的机械应变能随着石墨烯厚度增加到四次方，但与观察到的电化学能的增加相比，其幅度很小。据推测，机械应变能增加了锂分级的成核势垒，大大延迟了有序锂相的形成。这些结果表明，电极组件可能严重影响锂分级动力学。目前的工作表明，应变工程在二维（2D）纳米材料作为一种有效的方法来操纵相变和化学反应。
The development of next‐generation electrodes for metal‐ion batteries requires an understanding of intercalation dynamics in nanomaterials. Herein, it is shown that microscale mechanical strain significantly affects the formation of ordered lithium phases in graphene. In situ Raman spectroscopy of graphene microflakes mechanically constrained at the edge during lithium intercalation reveals a thickness‐dependent increase of up to 1.26 V in the electrochemical potential that induces lithium staging. While the induced mechanical strain energy increases with graphene thickness to the fourth power, its magnitude is small compared to the observed increase in electrochemical energy. It is hypothesized that the mechanical strain energy increases a nucleation barrier for lithium staging, greatly delaying the formation of ordered lithium phases. These results indicate that electrode assembly may critically impact lithium staging dynamics. The present work demonstrates strain engineering in two dimensional (2D) nanomaterials as an effective approach to manipulate phase transitions and chemical reactivity.