Double the Capacity of Manganese Spinel for Lithium‐Ion Storage by Suppression of Cooperative Jahn–Teller Distortion,Advanced Energy Materials

当前位置： X-MOL 学术 › Adv. Energy Mater. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Double the Capacity of Manganese Spinel for Lithium‐Ion Storage by Suppression of Cooperative Jahn–Teller Distortion
Advanced Energy Materials ( IF 24.4 ) Pub Date : 2020-07-26 , DOI: 10.1002/aenm.202000363
Changjian Zuo ₁ , Zongxiang Hu ₁ , Rui Qi ₁ , Jiajie Liu ₁ , Zhibo Li ₁ , Junliang Lu ₁ , Cheng Dong ₁ , Kai Yang ₁ , Weiyuan Huang ₁ , Cong Chen ₁ , Zhibo Song ₁ , Sicheng Song ₁ , Yaoming Yu ₁ , Jiaxin Zheng ₁ , Feng Pan ₁

Affiliation

The relatively low capacity and capacity fade of spinel LiMn₂O₄ (LMO) limit its application as a cathode material for lithium‐ion batteries. Extending the potential window of LMO below 3 V to access double capacity would be fantastic but hard to be realized, as it will lead to fast capacity loss due to the serious Jahn–Teller distortion. Here using experiments combined with extensive ab initio calculations, it is proved that there is a cooperative effect among individual Jahn–Teller distortions of Mn³⁺O₆ octahedrons in LMO, named as cooperative Jahn–Teller distortion (CJTD) in the text, which is the difficulty to access the capacity beyond one lithium intercalation. It is further proposed that the cationic disordering (excess Li at Mn sites and Li/Mn exchange) can intrinsically suppress the CJTD of Mn³⁺O₆ octahedrons. The cationic disordering can break the symmetry of Mn³⁺ arrangements to disrupt the correlation of distortions arising from individual JT centers and prevent the Mn³⁺O bonds distorting along one direction. Interestingly, with the suppressed CJTD, the original octahedral vacancies in spinel LMO are activated and can serve as extra Li‐ion storage sites to access the double capacity with good reversible cycling stability in microsized LMO.

中文翻译：

通过抑制合作的Jahn-Teller畸变，锰尖晶石的锂离子存储容量增加了一倍

尖晶石型LiMn ₂ O ₄（LMO）的相对较低的容量和容量衰减会限制其作为锂离子电池正极材料的应用。将LMO的潜在窗口扩展到3 V以下以获取双倍容量将是一件很了不起的事，但很难实现，因为由于严重的Jahn-Teller失真，它将导致容量快速损失。在这里，通过结合大量从头算的实验，证明了Mn ³⁺ O _6的各个Jahn–Teller畸变之间存在协同作用。改性活生物体中的八面体，在本文中称为合作Jahn-Teller畸变（CJTD），这是难以获得超出一种锂嵌入作用的容量的困难。进一步提出阳离子无序性（Mn位上过量的Li和Li / Mn交换）可以固有地抑制Mn ³⁺ O ₆八面体的CJTD 。阳离子无序可以破坏Mn ³⁺排列的对称性，从而破坏由各个JT中心引起的畸变的相关性，并防止Mn ³⁺O键沿一个方向变形。有趣的是，由于抑制了CJTD，尖晶石型LMO中的原始八面体空位被激活，可以用作额外的锂离子存储位点，从而在微型LMO中获得双倍容量并具有良好的可逆循环稳定性。

更新日期：2020-09-08

点击分享查看原文

点击收藏

阅读更多本刊最新论文本刊介绍/投稿指南11