The development of flame retardant or nonflammable electrolytes is the key to improve the safety of lithium batteries,owing to inflammable organic solvents and polymer matrix in common liquid and polymer electrolytes ...The development of flame retardant or nonflammable electrolytes is the key to improve the safety of lithium batteries,owing to inflammable organic solvents and polymer matrix in common liquid and polymer electrolytes regarded as the main cause of battery fire.Herein,a series of solid-state polyphosphate oligomers(SPPO)as a three-in-one electrolyte that integrated the roles of lithium salt,dissociation matrix,and flame retardant were synthesized.The well-designed SPPO electrolytes showed an optimal ionic conductivity of 5.5×10^(-4)S cm-1at 30℃,an acceptable electrochemical window up to 4.0 V vs.Li/Li+,and lithium ion transference number of 0.547.Stable Li-ion stripping/plating behavior for 500 h of charge-discharge cycles without internal short-circuit in a Li|SPPO|Li cell was confirmed,together with outstanding interface compatibility between the SPPO electrolyte and lithium foil.The optimal Li|SPPO|LiFePO4cell presented good reversible discharge capacity of 149.4 mA h g-1at 0.1 C and Coulombic efficiency of 96.4%after 120 cycles.More importantly,the prepared SPPO cannot be ignited by the lighter fire and show a limited-oxygen-index value as high as 35.5%,indicating splendid nonflammable nature.The SPPO could be a promising candidate as a three-in-one solid-state electrolyte for the improved safety of rechargeable lithium batteries.展开更多
The growing concern for the exhaustion of fossil energy and the rapid revolution of electronics have created a rising demand for electrical energy storage devices with high energy density,for example,lithium secondary...The growing concern for the exhaustion of fossil energy and the rapid revolution of electronics have created a rising demand for electrical energy storage devices with high energy density,for example,lithium secondary batteries(LSBs).With high surface area,low cost,excellent mechanical strength,and electrochemical stability,amorphous carbon-based materials(ACMs)have been widely investigated as promising platform for anode materials in the LSBs.In this review,we firstly summarize recent advances in the synthesis of the ACMs with various morphologies,ranging from zero-to three-dimensional structures.Then,the use of ACMs in Li-ion batteries and Li metal batteries is discussed respectively with the focus on the relationship between the structural features of the as-prepared ACMs and their roles in promoting electrochemical performances.Finally,the remaining challenges and the possible prospects for the use of ACMs in the LSBs are proposed to provide some useful clews for the future developments of this attractive area.展开更多
基金the financial support of the National Natural Science Foundation of China(21961044,22169024)the Yunnan Fundamental Research Projects(202105AC160072,202101BC070001-019,202101AT070280,202102AB080017)the Yunnan University’s Research Innovation Fund for graduate students(2021Y394)。
文摘The development of flame retardant or nonflammable electrolytes is the key to improve the safety of lithium batteries,owing to inflammable organic solvents and polymer matrix in common liquid and polymer electrolytes regarded as the main cause of battery fire.Herein,a series of solid-state polyphosphate oligomers(SPPO)as a three-in-one electrolyte that integrated the roles of lithium salt,dissociation matrix,and flame retardant were synthesized.The well-designed SPPO electrolytes showed an optimal ionic conductivity of 5.5×10^(-4)S cm-1at 30℃,an acceptable electrochemical window up to 4.0 V vs.Li/Li+,and lithium ion transference number of 0.547.Stable Li-ion stripping/plating behavior for 500 h of charge-discharge cycles without internal short-circuit in a Li|SPPO|Li cell was confirmed,together with outstanding interface compatibility between the SPPO electrolyte and lithium foil.The optimal Li|SPPO|LiFePO4cell presented good reversible discharge capacity of 149.4 mA h g-1at 0.1 C and Coulombic efficiency of 96.4%after 120 cycles.More importantly,the prepared SPPO cannot be ignited by the lighter fire and show a limited-oxygen-index value as high as 35.5%,indicating splendid nonflammable nature.The SPPO could be a promising candidate as a three-in-one solid-state electrolyte for the improved safety of rechargeable lithium batteries.
基金The authors acknowledge financial support by Leading Innovative and Entrepreneur Team Introduction Program of Zhejiang(No.2020R01002)the National Natural Science Foundation of China(Nos.21902144,51722210,51972285,and U1802254)the Natural Science Foundation of Zhejiang Province(Nos.LY17E020010 and LD18E020003).
文摘The growing concern for the exhaustion of fossil energy and the rapid revolution of electronics have created a rising demand for electrical energy storage devices with high energy density,for example,lithium secondary batteries(LSBs).With high surface area,low cost,excellent mechanical strength,and electrochemical stability,amorphous carbon-based materials(ACMs)have been widely investigated as promising platform for anode materials in the LSBs.In this review,we firstly summarize recent advances in the synthesis of the ACMs with various morphologies,ranging from zero-to three-dimensional structures.Then,the use of ACMs in Li-ion batteries and Li metal batteries is discussed respectively with the focus on the relationship between the structural features of the as-prepared ACMs and their roles in promoting electrochemical performances.Finally,the remaining challenges and the possible prospects for the use of ACMs in the LSBs are proposed to provide some useful clews for the future developments of this attractive area.
