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Regulating the Li + ‐Solvation Structure of Ester Electrolyte for High‐Energy‐Density Lithium Metal Batteries
Author(s) -
Xiao Dengji,
Li Qian,
Luo Dan,
Li Gaoran,
Liu Hao,
Shui Lingling,
Gourley Storm,
Zhou Guofu,
Wang Xin,
Chen Zhongwei
Publication year - 2020
Publication title -
small
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.785
H-Index - 236
eISSN - 1613-6829
pISSN - 1613-6810
DOI - 10.1002/smll.202004688
Subject(s) - electrolyte , solvation , lithium (medication) , faraday efficiency , cathode , battery (electricity) , chemical engineering , materials science , electrochemistry , dissolution , lithium battery , chemistry , inorganic chemistry , ionic bonding , ion , electrode , organic chemistry , thermodynamics , medicine , power (physics) , physics , engineering , endocrinology
The development of high‐energy‐density Li metal batteries are hindered by electrolyte consumption and uneven lithium deposition due to the unstable lithium‐electrolyte interface (SEI). In this work, tetraglyme is introduced into ester electrolyte to regulate the Li + ‐solvation structures for stable SEI while remaining appropriate voltage window for high‐voltage cathodes. In the modified solvation structures, an enhanced lowest unoccupied molecular orbital energy level occurs, resulting in relieved electrolyte degradation. In addition, the modified solvation structures can facilitate adequate LiNO 3 dissolution in the ester electrolyte (denoted as E‐LiNO 3 ), contributing to constant supplement of constructing highly conductive LiN x O y ‐containing SEI for dendrite‐free Li deposition under high capacity condition. As a result, the Li||Cu cell‐based on this electrolyte exhibits high Li plating/stripping Coulombic efficiency of 98.2% over 350 cycles. Furthermore, when paired with high‐voltage LiNi 0.5 Co 0.2 Mn 0.3 O 2 cathodes, the E‐LiNO 3 enables a stable cycling with a high‐energy‐density of 296 Wh kg −1 based on the full cell under realistic testing conditions (lean electrolyte of 3 g Ah −1 , limited Li excess of 2.45‐fold, and high areal capacity of 4 mAh cm −2 ).