Non-Flammable Electrolyte Mediated by Solvation Chemistry toward High-Voltage Lithium-Ion Batteries

Abstract

The development of nonflammable electrolytes can boost energy density and battery safety, especially for layered metal oxide cathodes operating at high voltage. However, most nonflammable electrolytes are designed in a high concentration for compatibility with graphite electrodes and/or less decomposition. Herein, we introduced a solvation structure-mediated model to develop a nonflammable electrolyte based on trimethyl phosphate (TMP) solvent at a normal concentration. This advancement allows the graphite || lithium cobalt oxide full cell to operate at 4.5 V, delivering high energy density and also exhibiting a nonflammable feature. This achievement is realized using previously unreported components, including carbonate solvent, ethylene sulfate (DTD) additives, and conventional LiPF 6 salt. We analyzed the molecular behaviors of each electrolyte composition and also uncovered the unreported impact of DTD, highlighting its prerequisite conditions for effectively weakening the Li + -TMP interactions. This bottom-up design strategy offers a fresh perspective on regulating solvation structures and electrolyte formulations.

Trace ethylene carbonate-mediated low-concentration ether-based electrolytes for high-voltage lithium metal batteries

“…These results further demonstrate the excellent capacity of the LED electrolyte with high-voltage cathodes and lithium anodes. 58 The comparative results also illustrate the effectiveness of using EC to solubilize lithium salts and adjust the solvation structure, showcasing promising prospects for application and development.…”

Formulating compatible non-flammable electrolyte for lithium-ion batteries with ethoxy (pentafluoro) cyclotriphosphazene

“…[12][13][14] Balancing the ame-retarding effect and the electrochemical performance of electrolytes remains a great challenge till now. [15][16][17][18] Herein, ethoxy (pentauoro) cyclotriphosphazene (PFPN) was applied as the ame-retarding additive for Li ion battery electrolyte. The ammability of electrolyte was greatly suppressed with introduction of only 3 wt% PFPN.…”

“… 12–14 Balancing the flame-retarding effect and the electrochemical performance of electrolytes remains a great challenge till now. 15–18 …”

Low-Temperature and Fast-Charging Lithium Metal Batteries Enabled by Solvent–Solvent Interaction Mediated Electrolyte

“…Furthermore, some electrolyte formulations are not derived from commercialized carbonate-based electrolytes, posing challenges for practical applications . Similar challenges exist in ether-based electrolytes, including solvent volatility, increased cost of high concentration and/or new molecules, and difficulties in stable cycling at high-voltage operations, making commercialization challenging. − Thus, designing a compatible electrolyte that is readily commercializable while elucidating design principles and understanding the relationship between electrolyte composition and battery performance remains a significant challenge. − …”