Jia Hao, Kim Ju-Myung, Gao Peiyuan, Xu Yaobin, Engelhard Mark H, Matthews Bethany E, Wang Chongmin, Xu Wu
Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland, WA 99354, USA.
Physical & Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA 99354, USA.
Angew Chem Int Ed Engl. 2023 Apr 17;62(17):e202218005. doi: 10.1002/anie.202218005. Epub 2023 Mar 20.
Localized high-concentration electrolytes (LHCEs) based on five different types of solvents were systematically studied and compared in lithium (Li)-ion batteries (LIBs). The unique solvation structure of LHCEs promotes the participation of Li salt in forming solid electrolyte interphase (SEI) on graphite (Gr) anode, which enables solvents previously considered incompatible with Gr to achieve reversible lithiation/delithiation. However, the long cyclability of LIBs is still subject to the intrinsic properties of the solvent species in LHCEs. Such issue can be readily resolved by introducing a small amount of additive into LHCEs. The synergetic decompositions of Li salt, solvating solvent and additive yield effective SEIs and cathode electrolyte interphases (CEIs) in most of the studied LHCEs. This study reveals that both the structure and the composition of solvation sheaths in LHCEs have significant effect on SEI and CEI, and consequently, the cycle life of energetically dense LIBs.
在锂离子电池（LIBs）中，对基于五种不同类型溶剂的局部高浓度电解质（LHCEs）进行了系统研究和比较。LHCEs独特的溶剂化结构促进锂盐参与在石墨（Gr）阳极上形成固体电解质界面（SEI），这使得以前被认为与Gr不相容的溶剂能够实现可逆的锂化/脱锂。然而，LIBs的长循环寿命仍然取决于LHCEs中溶剂种类的固有特性。通过在LHCEs中引入少量添加剂，可以很容易地解决这个问题。在大多数研究的LHCEs中，锂盐、溶剂化溶剂和添加剂的协同分解产生了有效的SEIs和阴极电解质界面（CEIs）。这项研究表明，LHCEs中溶剂化鞘层的结构和组成对SEI和CEI都有显著影响，因此对能量密度高的LIBs的循环寿命也有显著影响。
