The combination of high-nickel cathodes with lithium metal anodes is widely considered a promising solution to alleviate range anxiety. However, challenges such as limited fast-charging capacity and rapid degradation persist when using carbonate-based electrolytes. While many researchers predominantly focus on solvation structures, we have strategically tailored the electrolyte formulation by employing isopropyl acetate as the primary solvent, evidenced by interfacial interactions. Compared to n-propyl acetate, isopropyl acetate reduced the interaction with the electrode surface, promoted tighter adsorption of the electrolyte ion network within the inner Helmholtz layer, and ultimately enhanced the dynamic stability of the lithium metal interface. In Li‖NCM811 cells, this electrolyte demonstrates a 4.5 V cutoff and sustains 88.6% capacity retention over 200 cycles at a high rate of 15C. Additionally, this electrolyte demonstrates stable cycling performance at elevated rates of 1C and 5C at temperatures of 60 °C and −20 °C, respectively, while maintaining stability even at a rate of 10C under poor electrolyte conditions with thin lithium layers, indicating significant application potential. These studies reveal that the electrolyte distribution at the electrode interface affects the electrochemical process and the formation of the electrode–electrolyte interphase significantly, offering new ideas for future electrolyte research and design.
Lithium-ion batteries, with high energy density and long cycle life, have become the battery of choice for most vehicles and portable electronic devices; however, energy density, safety and cycle life require further improvements. Single-functional group electrolyte additives are very limited in practical applications, a ternary polymer bifunctional electrolyte additive copolymer (acrylonitrile-butyl hexafluoro methacrylate- poly (ethylene glycol) methacrylate- methyl ether) (PMANHF) was synthesized by free radical polymerization of acrylonitrile, 2, 2, 3, 4, 4, 4-hexafluorobutyl methacrylate and poly (ethylene glycol) methyl ether methacrylate. A series of characterizations show that in Li metal anodes, the preferential reduction of PMANHF is conducive to the formation of a uniform and stable solid electrolyte interphase layer, and Li deposition is uniform and dense. At the NCM811 cathode, a film composed of LiF- and Li3N-rich is formed at the cathode-electrolyte interface, mitigating the side reaction at the interface. At 1.0 mA cm-2, the Li/Li cell can be stabilized for 1000 cycles. In addition, the Li/NCM811 cell can stabilize 200 cycles with a cathode capacity of 153.7 mAh g-1, with the capacity retention of 89.93%, at a negative/positive capacity ratio of 2.5. This study brings to light essential ideas for the fabrication of additives for lithium-metal batteries.
危险品化学品经营许可证（带存储）