Ober Seamus, Manthiram Arumugam
Materials Science and Engineering Program & Texas Materials Institute, The University of Texas at Austin, Austin, TX, 78712, USA.
Small. 2024 Nov;20(47):e2405731. doi: 10.1002/smll.202405731. Epub 2024 Aug 13.
Localized high-concentration electrolytes (LHCEs) have emerged as a promising class of electrolytes to improve the cycle life and energy density of lithium-ion batteries (LIBs). While their application in batteries with lithium-metal anodes is extensively investigated, their behavior in systems with graphite anodes has received less research attention. Herein, the behaviors of four electrolytes in Graphite | LiNiO cells are compared. By systematically varying the electrolyte compositions, the impacts of the solvation structure, solvent composition, and salt composition of LHCEs are identified on the rate capability, stability, and propensity for lithium plating in LIB full-cells. It is found that while the solvation structure and solvent composition each play an important role in determining rate capability, the substitution of LiPF salt with LiFSI maximizes the rate capability and suppresses irreversible lithium plating. It is now demonstrated via constant-potential cycling, that an appropriately formulated LHCE can, therefore, maintain high reversible capacity and safety under arbitrarily fast charging conditions.
局部高浓度电解质（LHCEs）已成为一类有前景的电解质，可改善锂离子电池（LIBs）的循环寿命和能量密度。虽然它们在锂金属负极电池中的应用得到了广泛研究，但它们在石墨负极系统中的行为受到的研究关注较少。在此，比较了四种电解质在石墨|LiNiO电池中的行为。通过系统地改变电解质组成，确定了LHCEs的溶剂化结构、溶剂组成和盐组成对LIB全电池的倍率性能、稳定性和锂金属沉积倾向的影响。研究发现，虽然溶剂化结构和溶剂组成在决定倍率性能方面都起着重要作用，但用LiFSI替代LiPF盐可使倍率性能最大化并抑制不可逆的锂金属沉积。因此现在通过恒电位循环证明，适当配制的LHCE在任意快速充电条件下都能保持高可逆容量和安全性。
