The poor compatibility of ester electrolytes with lithium metal anode severely limits its use in high voltage lithium metal batteries(LMBs).In this work,a bidentate solvent 1,2-diethoxyethane(DEE) is introduced into e...The poor compatibility of ester electrolytes with lithium metal anode severely limits its use in high voltage lithium metal batteries(LMBs).In this work,a bidentate solvent 1,2-diethoxyethane(DEE) is introduced into ester electrolyte to regulate the ion-dipole interactions to enhance the solubility of LiNO_(3),which enables compatibility with Li anode and maintains the high voltage cathode stability.In the designed electrolyte,the steric effect of DEE facilitates the participation of NO_(3)^(-)and PF_6^(-)anions in the Li^(+) solvation structure,thus promoting the generation of inorganic-rich solid electrolyte interphase(SEI).And the low viscosity of DEE also ensures that the ester electrolyte poses good interracial wettability.As a result,our designed electrolyte enables the high-loading Li‖NCM622 and Li‖NCM811(^(3) mA h cm^(-2)) full cells to achieve stable cycling over 200 cycles,8 times longer than that of a conventional ester electrolyte.This work suggests that regulation of intermolecular interactions in conventional ester electrolytes is a scalable and effective approach to achieve excellent electrochemical performance of LMBs.展开更多
Lithium (Li) metal is a promising anode for the next generation high-energy–density batteries. However, the growth of Li dendrites, low coulombic efficiency and dramatic volume change limit its development. Here, we ...Lithium (Li) metal is a promising anode for the next generation high-energy–density batteries. However, the growth of Li dendrites, low coulombic efficiency and dramatic volume change limit its development. Here, we report a new synthetic poly-dioxolane (PDOL) approach to constructing an artificial 'elastic' SEI to stabilize the Li/electrolyte interface and the Li deposition/dissolution behavior in a variety of electrolytes. By coating PDOL with optimized molecular weights and synthetic routes on Li metal anode, the 'elastic' SEI layer could be maintained on top of the Li metal anode to accommodate the Li deposition/dissolution. No dendrite formation was observed during the cycling process, and the interfacial side reactions were reduced significantly. Consequently, we successfully achieved 330 cycles with a CE of 98.4% in ether electrolytes and 90 cycles with a CE of 94.3% in carbonate electrolytes. Simultaneously, the Li-metal batteries with LiFePO_(4) as cathodes also exhibited improved cycling performance. This strategy could promote the development of dendrite-free metal anodes toward high-performance Li-metal batteries.展开更多
Perfluoropolyether(PFPE)is a promising material for protective coatings on Li metal anodes due to its chemical inertness and minimal swelling in electrolytes.However,a conventional PFPE coating with poor ionic conduct...Perfluoropolyether(PFPE)is a promising material for protective coatings on Li metal anodes due to its chemical inertness and minimal swelling in electrolytes.However,a conventional PFPE coating with poor ionic conductivity and mechanical stability is still not satisfactory for long-term cycling of Li anodes.Here,we design and synthesize an adaptive and high-conductivity supramolecular polymer(PFPE-EG-I).This polymer is constructed from PFPE chains,ethylene glycol(EG)segments,and hydrogen-bonding moieties derived from isophoronediisocyanate,serving as a multifaceted artificial solid electrolyte interphase(SEI).The incorporated EG segments enhance the Li+conductivity of the SEI,and the hydrogen-bonding units introduce a dynamic self-adaptive behavior to the polymer matrix.A solution-processed PFPE-EG-I coating is demonstrated to promote uniform Li deposition and mitigate side reactions between Li and the electrolyte.Consequently,this leads to enhanced coulombic efficiency and prolonged cycle longevity in lithium metal batteries(LMBs).The innovative design of this multifunctional artificial SEI offers a promising avenue for the realization of dendrite-free Li anodes,paving the way for the advancement of high-performance LMBs.展开更多
基金financially National Natural Science Foundation of China (Grant No. 22209134)Fundamental Research Funds for the Central Universities, Southwest Minzu University (Grant No. ZYN2023003)+1 种基金Sichuan Science and Technology Program (Grant No. 2024NSFSC1155)Fundamental Research Funds for the Central Universities, Southwest Jiaotong University (Grant No. 2682023CX005)。
文摘The poor compatibility of ester electrolytes with lithium metal anode severely limits its use in high voltage lithium metal batteries(LMBs).In this work,a bidentate solvent 1,2-diethoxyethane(DEE) is introduced into ester electrolyte to regulate the ion-dipole interactions to enhance the solubility of LiNO_(3),which enables compatibility with Li anode and maintains the high voltage cathode stability.In the designed electrolyte,the steric effect of DEE facilitates the participation of NO_(3)^(-)and PF_6^(-)anions in the Li^(+) solvation structure,thus promoting the generation of inorganic-rich solid electrolyte interphase(SEI).And the low viscosity of DEE also ensures that the ester electrolyte poses good interracial wettability.As a result,our designed electrolyte enables the high-loading Li‖NCM622 and Li‖NCM811(^(3) mA h cm^(-2)) full cells to achieve stable cycling over 200 cycles,8 times longer than that of a conventional ester electrolyte.This work suggests that regulation of intermolecular interactions in conventional ester electrolytes is a scalable and effective approach to achieve excellent electrochemical performance of LMBs.
基金This research was supported financially by the Major Program of the National Natural Science Foundation of China(21890731).
文摘Lithium (Li) metal is a promising anode for the next generation high-energy–density batteries. However, the growth of Li dendrites, low coulombic efficiency and dramatic volume change limit its development. Here, we report a new synthetic poly-dioxolane (PDOL) approach to constructing an artificial 'elastic' SEI to stabilize the Li/electrolyte interface and the Li deposition/dissolution behavior in a variety of electrolytes. By coating PDOL with optimized molecular weights and synthetic routes on Li metal anode, the 'elastic' SEI layer could be maintained on top of the Li metal anode to accommodate the Li deposition/dissolution. No dendrite formation was observed during the cycling process, and the interfacial side reactions were reduced significantly. Consequently, we successfully achieved 330 cycles with a CE of 98.4% in ether electrolytes and 90 cycles with a CE of 94.3% in carbonate electrolytes. Simultaneously, the Li-metal batteries with LiFePO_(4) as cathodes also exhibited improved cycling performance. This strategy could promote the development of dendrite-free metal anodes toward high-performance Li-metal batteries.
基金National Natural Science Foundation of China(grant no.22075164)Fundamental Research Funds for the Central Universities,Southwest Jiaotong University(grant no.2682023CX005).
文摘Perfluoropolyether(PFPE)is a promising material for protective coatings on Li metal anodes due to its chemical inertness and minimal swelling in electrolytes.However,a conventional PFPE coating with poor ionic conductivity and mechanical stability is still not satisfactory for long-term cycling of Li anodes.Here,we design and synthesize an adaptive and high-conductivity supramolecular polymer(PFPE-EG-I).This polymer is constructed from PFPE chains,ethylene glycol(EG)segments,and hydrogen-bonding moieties derived from isophoronediisocyanate,serving as a multifaceted artificial solid electrolyte interphase(SEI).The incorporated EG segments enhance the Li+conductivity of the SEI,and the hydrogen-bonding units introduce a dynamic self-adaptive behavior to the polymer matrix.A solution-processed PFPE-EG-I coating is demonstrated to promote uniform Li deposition and mitigate side reactions between Li and the electrolyte.Consequently,this leads to enhanced coulombic efficiency and prolonged cycle longevity in lithium metal batteries(LMBs).The innovative design of this multifunctional artificial SEI offers a promising avenue for the realization of dendrite-free Li anodes,paving the way for the advancement of high-performance LMBs.
