Additive‐guided Solvation‐regulated Flame‐retardant Electrolyte Enables High‐voltage Lithium Metal Batteries with Robust Electrode Electrolyte Interphases

Abstract

Widening the voltage window of the nickel‐rich layered oxide cathode‐based lithium metal batteries (LMBs) can effectively improve the energy density of rechargeable batteries. However, serious safety issues associated with the high reactivity between LiNi0.8Co0.1Mn0.1O2 (NCM811) and electrolyte at high cut‐off voltage remains challenging. Herein, a flame‐retardant electrolyte with the ability to form a robust armor‐like electrode electrolyte interphase (EEI) with LiF and LixByOz compounds for stabilizing Li||NCM811 batteries is proposed. Such electrolyte exhibits the high thermal stability with flame‐retardant effect for ensuring the battery safety at high voltage. The armor‐like EEI can effectively protect both NCM811 and lithium (Li) for improving the battery cycling performance. As a result, the capacity retention rate of the NCM811 cathode with such electrolyte reached 68% after 150 cycles at 4.6 V. This work provides an effective reference for the reasonable design of high‐voltage, flame‐retardant electrolytes for LMBs.

In situ polymerization of 1,3-dioxolane and formation of fluorine/boron-rich interfaces enabled by film-forming additives for long-life lithium metal batteries

“…4f and j), indicating the involvement of THB in generating LiB x O y inorganic compounds that establish a cross-linked covalent backbone, ensuring the formation of stable and robust SEIs. 43,50 Elemental analyses revealed that the THB was involved in the formation of SEIs enriched in B and F (Fig. S15 and Table S1†).…”

“…The THB-PDOL forms polymer–inorganic composite SEIs, where the long-chain composition of polymer component enhanced flexibility to the SEI, enabling it to adapt to rapid changes in electrode volume during lithium plating/stripping. 40,50 Additionally, the abundant inorganic component ensures the uniformity of lithium ion transport within the SEI, which is essential for preventing the formation of lithium dendrites on lithium metal anodes.…”

Review on Oxygen Release Mechanism and Modification Strategy of Nickel-Rich NCM Cathode Materials for Lithium-Ion Batteries: Recent Advances and Future Directions

“…The electrolyte system exhibits good flame retardancy due to the presence of TEP, while TMB was able to reduce the entry of TEP and PF 6 − into the solvation structure of Li + and inhibit the decomposition of TEP and PF 6 − , stabilizing the structure of NCM811 and inhibiting the dissolution of transition metals and the formation of Li dendrites, which led to the improvement of battery performance. 220 In addition, multifunctional single additives with excellent properties are also the focus of future research. For example, amine-functionalized mesoporous molecular sieve (NASM) additive can construct multifunctional self-reconstructing CEI layers with modified mechanical properties as well as electrochemical stability and simultaneously generate additiveinduced antifluorination protective layer, which can improve the cycling stability of the battery.…”

“…Liu et al developed an electrolyte system consisting of fluorinated ethylene carbonate (FEC), ethylmethyl carbonate (EMC), and triethyl phosphate (TEP) as solvents, and trimethyl borate­(TMB) as additives, which were able to build armor-like CEI and SEI. The electrolyte system exhibits good flame retardancy due to the presence of TEP, while TMB was able to reduce the entry of TEP and PF 6 – into the solvation structure of Li + and inhibit the decomposition of TEP and PF 6 – , stabilizing the structure of NCM811 and inhibiting the dissolution of transition metals and the formation of Li dendrites, which led to the improvement of battery performance . In addition, multifunctional single additives with excellent properties are also the focus of future research.…”

M2+-Doped Nickel Selenide Nanoflowers (M = Co, Cu, and Zn) for Supercapacitors

“…New energy storage devices with high energy/power density, including supercapacitors (SCs) and lithium metal batteries (LMBs), have obtained increasing interest for the fast development of electric vehicles. − Transition-metal selenides (TMSes) have aroused much attention due to their unique optical and electronic properties, making them potential materials for applications in SCs, photocatalysis, and electrocatalysis. − Metal–Se bond is weaker than metal–O and metal–S bonds, which is kinetically favored over the conversion reaction; moreover, TMSes possess a special d -electronic structure and adjustable coordination environment. , Hence, TMSes are more suitable as electrode materials for SCs compared with transition-metal oxides/sulfides. Additionally, the electronic conductivity of half-metallic Se is larger than that of nonmetallic S (1 × 10 –5 vs 5 × 10 –28 S m –1 ); therefore, TMSes have gained tremendous attention in the field of SCs .…”