Gel polymer electrolytes(GPEs)are one of the promising candidates for high-energy-density quasi-solid-state lithium metal batteries(QSSLMBs),for their high ionic conductivity and excellent interfacial compatibility.Th...Gel polymer electrolytes(GPEs)are one of the promising candidates for high-energy-density quasi-solid-state lithium metal batteries(QSSLMBs),for their high ionic conductivity and excellent interfacial compatibility.The comprehension of dynamic evolution and structure-reactivity correlation at the GPE/Li interface becomes significant.Here,in situ electrochemical atomic force microscopy(EC-AFM)provides insights into the LiNO_(3)-regulated micromechanism of the Li plating/stripping processes upon cycles in GPE-based LMBs at nanoscale.The additive LiNO_(3)induces the formation of amorphous nitride SEI film and facilitates Li^(+) ion diffusion.It stabilizes a compatible interface and regulates the Li nucleation/growth at steady kinetics.The deposited Li is in the shape of chunks and tightly compact.The Li dissolution shows favorable reversibility,which guarantees the cycling performance of LMBs.In situ AFM monitoring provides a deep understanding into the dynamic evolution of Li deposition/dissolution and the interphasial properties of tunable SEI film,regulating the rational design of electrolyte and optimizing interfacial establishment for GPE-based QSSLMBs.展开更多
Hard carbon derived from biomass is regarded as a promising anode material for sodium-ion batteries(SIBs)because of its low operating potential,high capacity,resource availability,and low cost.However,scientific and t...Hard carbon derived from biomass is regarded as a promising anode material for sodium-ion batteries(SIBs)because of its low operating potential,high capacity,resource availability,and low cost.However,scientific and technological challenges still exist to prepare hard carbon with a high initial Coulombic efficiency(ICE),an excellent rate capability,and good cycling stability.In this work,we report a self-supported hard carbon electrode from fungus-pretreated basswood with an improved graphitization degree and a low tortuosity.Compared with the hard carbon derived from basswood,the hard carbon electrode from fungus-pretreated basswood has an improved rate capability of 242.3 mAh·g^(−1)at 200 mA·g^(−1)and cycling stability with 93.9%of its capacity retention after 200 cycles at 40 mA·g^(−1),as well as the increased ICE from 84.3%to 88.2%.Additionally,ex-situ X-ray diffraction indicates that Na+adsorption caused the sloping capacity,whereas Na+intercalation between interlayer spacing corresponded to the low potential plateau capacity.This work provides a new perspective for the preparation of high-performance hard carbon and gains the in-depth understanding of Na storage mechanism.展开更多
基金financially supported by the National Key R&D Program of China(Grant No.2016YFA0202500)the National Natural Science Fund for Excellent Young Scholars(Grant No.21722508)。
文摘Gel polymer electrolytes(GPEs)are one of the promising candidates for high-energy-density quasi-solid-state lithium metal batteries(QSSLMBs),for their high ionic conductivity and excellent interfacial compatibility.The comprehension of dynamic evolution and structure-reactivity correlation at the GPE/Li interface becomes significant.Here,in situ electrochemical atomic force microscopy(EC-AFM)provides insights into the LiNO_(3)-regulated micromechanism of the Li plating/stripping processes upon cycles in GPE-based LMBs at nanoscale.The additive LiNO_(3)induces the formation of amorphous nitride SEI film and facilitates Li^(+) ion diffusion.It stabilizes a compatible interface and regulates the Li nucleation/growth at steady kinetics.The deposited Li is in the shape of chunks and tightly compact.The Li dissolution shows favorable reversibility,which guarantees the cycling performance of LMBs.In situ AFM monitoring provides a deep understanding into the dynamic evolution of Li deposition/dissolution and the interphasial properties of tunable SEI film,regulating the rational design of electrolyte and optimizing interfacial establishment for GPE-based QSSLMBs.
基金supported by the National Key Research and Development Program of China(No.2021YFA2400400)the National Natural Science Foundation of China(Nos.22109058,22122902,22075299,and 21975091)+3 种基金the Fundamental Research Funds for the Central Universities of China(No.20230614)the Jiangxi Provincial Education Department(No.GJJ200338)the Open Fund of Fujian Provincial Engineering Technology Research Center of Solar Energy Conversion and Energy Storage(No.SECES2003)Beijing Natural Science Foundation(No.2222089).
文摘Hard carbon derived from biomass is regarded as a promising anode material for sodium-ion batteries(SIBs)because of its low operating potential,high capacity,resource availability,and low cost.However,scientific and technological challenges still exist to prepare hard carbon with a high initial Coulombic efficiency(ICE),an excellent rate capability,and good cycling stability.In this work,we report a self-supported hard carbon electrode from fungus-pretreated basswood with an improved graphitization degree and a low tortuosity.Compared with the hard carbon derived from basswood,the hard carbon electrode from fungus-pretreated basswood has an improved rate capability of 242.3 mAh·g^(−1)at 200 mA·g^(−1)and cycling stability with 93.9%of its capacity retention after 200 cycles at 40 mA·g^(−1),as well as the increased ICE from 84.3%to 88.2%.Additionally,ex-situ X-ray diffraction indicates that Na+adsorption caused the sloping capacity,whereas Na+intercalation between interlayer spacing corresponded to the low potential plateau capacity.This work provides a new perspective for the preparation of high-performance hard carbon and gains the in-depth understanding of Na storage mechanism.