Sodium-ion batteries(SIBs)have attracted considerable interest as an alternative to lithium-ion batteries owing to their similar electrochemical performance and superior long-term cycle stability.Organic materials are...Sodium-ion batteries(SIBs)have attracted considerable interest as an alternative to lithium-ion batteries owing to their similar electrochemical performance and superior long-term cycle stability.Organic materials are regarded as promising anode materials for constructing SIBs with high capacity and good retention.However,utilization of organic materials is rather limited by their low energy density and poor stability at high current densities.To overcome these limitations,we utilized a novel polymeric disodium phthalocyanines(pNaPc)as SIB anodes to provide stable coordination sites for Na ions as well as to enhance the stability at high current density.By varying the linker type during a one-pot cyclization and polymerization process,two pNaPc anodes with O-(O-pNaPc)and S-linkers(S-pNaPc)were prepared,and their structural and electrochemical properties were investigated.The O-pNaPc binds Na ions with a lower binding energy compared with S-pNaPc,which leads to more facile Na-ion coordination/dissociation when engaged as SIB anode.The use of O-pNaPc significantly improves the redox kinetics and cycle stability and allows the fabrication of a full cell against Na_(3)V_(2)(PO_(4))_(2)F_(3)/C cathode,which demonstrates its practical application with high energy density(288 Wh kg^(-1))and high power density(149 W kg^(-1)).展开更多
Herein,we report the molecular engineering of anion-fluxing polymeric metal phthalocyanines(MTPs)by controlling the types of metal centers and incorporating lithiophilic linkers to achieve ultrastable Li metal batteri...Herein,we report the molecular engineering of anion-fluxing polymeric metal phthalocyanines(MTPs)by controlling the types of metal centers and incorporating lithiophilic linkers to achieve ultrastable Li metal batteries.Spectroscopic characterization,cryogenic transmission electron microscopy,and computational simulations demonstrate that the Co-N_(4) sites of Co in the incorporated MTP(CoTP)facilitate the local accumulation and directional flux of TFSI anions,inducing the formation of uniform,dense LiF-rich solid electrolyte interphases.As a result of this interfacial chemistry,symmetric cells with CoTP@CC-Li exhibited outstanding cycling stability,exceeding 2500 h at 1 mA cm^(-2) and 1 mAh cm^(-2).CoTP@CC-Li||LiFePO_(4) full cells operated stably for over 600 cycles under fast charge/discharge conditions,with a high-mass-loading cathode of 20 mg cm^(-2).CoTP@CC-Li||LiFePO_(4) pouch cells demonstrated stable cyclability under demanding practical conditions,including a low N/P ratio of 2.5,high cathode mass loading(23.53 mg cm^(-2)),and lean electrolyte usage(5 g Ah^(-1)).Furthermore,CoTP@CC-enabled anode-free full cells achieved exceptional stability over 500 cycles,even under stringent conditions(NCM811 mass loading of 20 mg cm^(-2) and lean electrolyte usage of 3 g Ah^(-1)).These results highlight the effectiveness of the anion-flux interfacial engineering strategy for enabling stable and reversible Li deposition under demanding conditions.展开更多
基金financial supports from the Research Grants Council of the Hong Kong Special Administrative Region(Poly U15217521)the Hong Kong Polytechnic University(Q-CDA3)Initiative for fostering University of Research and Innovation Program of the National Research Foundation(NRF)funded by the Korean government(MSIT)(No.2020M3H1A1077095)
文摘Sodium-ion batteries(SIBs)have attracted considerable interest as an alternative to lithium-ion batteries owing to their similar electrochemical performance and superior long-term cycle stability.Organic materials are regarded as promising anode materials for constructing SIBs with high capacity and good retention.However,utilization of organic materials is rather limited by their low energy density and poor stability at high current densities.To overcome these limitations,we utilized a novel polymeric disodium phthalocyanines(pNaPc)as SIB anodes to provide stable coordination sites for Na ions as well as to enhance the stability at high current density.By varying the linker type during a one-pot cyclization and polymerization process,two pNaPc anodes with O-(O-pNaPc)and S-linkers(S-pNaPc)were prepared,and their structural and electrochemical properties were investigated.The O-pNaPc binds Na ions with a lower binding energy compared with S-pNaPc,which leads to more facile Na-ion coordination/dissociation when engaged as SIB anode.The use of O-pNaPc significantly improves the redox kinetics and cycle stability and allows the fabrication of a full cell against Na_(3)V_(2)(PO_(4))_(2)F_(3)/C cathode,which demonstrates its practical application with high energy density(288 Wh kg^(-1))and high power density(149 W kg^(-1)).
基金supported by the National Research Foundation(NRF)of Korea grant funded by the Korea government(MSIT)(No.RS-2020-NR049409 and No.RS-2023-00217581)the computational time provided by Korea Institute of Science and Technology Information(KISTI)(KSC-2023-CRE-0414).
文摘Herein,we report the molecular engineering of anion-fluxing polymeric metal phthalocyanines(MTPs)by controlling the types of metal centers and incorporating lithiophilic linkers to achieve ultrastable Li metal batteries.Spectroscopic characterization,cryogenic transmission electron microscopy,and computational simulations demonstrate that the Co-N_(4) sites of Co in the incorporated MTP(CoTP)facilitate the local accumulation and directional flux of TFSI anions,inducing the formation of uniform,dense LiF-rich solid electrolyte interphases.As a result of this interfacial chemistry,symmetric cells with CoTP@CC-Li exhibited outstanding cycling stability,exceeding 2500 h at 1 mA cm^(-2) and 1 mAh cm^(-2).CoTP@CC-Li||LiFePO_(4) full cells operated stably for over 600 cycles under fast charge/discharge conditions,with a high-mass-loading cathode of 20 mg cm^(-2).CoTP@CC-Li||LiFePO_(4) pouch cells demonstrated stable cyclability under demanding practical conditions,including a low N/P ratio of 2.5,high cathode mass loading(23.53 mg cm^(-2)),and lean electrolyte usage(5 g Ah^(-1)).Furthermore,CoTP@CC-enabled anode-free full cells achieved exceptional stability over 500 cycles,even under stringent conditions(NCM811 mass loading of 20 mg cm^(-2) and lean electrolyte usage of 3 g Ah^(-1)).These results highlight the effectiveness of the anion-flux interfacial engineering strategy for enabling stable and reversible Li deposition under demanding conditions.
