Lithium-ion capacitors(LICs)are regarded as a good choice for next-generation energy storage devices,which are expected to exhibit high energy densities,high power densities,and ultra-long cycling stability.Neverthele...Lithium-ion capacitors(LICs)are regarded as a good choice for next-generation energy storage devices,which are expected to exhibit high energy densities,high power densities,and ultra-long cycling stability.Nevertheless,only a few battery-type cathode materials with limited kinetic properties can be employed in LICs,and their electrochemical properties need to be optimized urgently.Here,we exploit a new dendrite-structured FeF_(2) consisting of closely linked primary nanoparticles using a facile solvothermal method combined with the subsequent annealing treatment.This particular architecture has favorable transport pathways for both lithium ions and electrons and exhibits an ultrafast chargedischarge capability with high reversible capacities.Furthermore,a well-designed LIC employing the prepared dendrite-structured FeF_(2) as the battery-type cathode and commercialized activated carbon(AC)as supercapacitor-type anode was constructed in an organic electrolyte containing Li ions.The LIC operates at an optimal voltage range of 1.1-3.8 V and shows a maximum high energy density of 152 W h kg^(-1) and a high power density of 4900 W kg^(-1) based on the total mass of cathode and anode.Long-term cycling stability(85%capacity retention after 2000 cycles)was achieved at 1 A g^(-1).This work suggests that the dendrite-structured FeF_(2) is a prime candidate for high-performance LICs and accelerates the development of hybrid ion capacitor devices.展开更多
基金funding support from the National Natural Science Foundation of China(51804173)the Shandong Provincial Natural Science Foundation(ZR2018BB030)+1 种基金the Qingdao Science and Technology Plan Applied Basic Research(Youth Special Project,18-2-2-22-jch)the funding support from “Distinguished Taishan Scholar”project。
文摘Lithium-ion capacitors(LICs)are regarded as a good choice for next-generation energy storage devices,which are expected to exhibit high energy densities,high power densities,and ultra-long cycling stability.Nevertheless,only a few battery-type cathode materials with limited kinetic properties can be employed in LICs,and their electrochemical properties need to be optimized urgently.Here,we exploit a new dendrite-structured FeF_(2) consisting of closely linked primary nanoparticles using a facile solvothermal method combined with the subsequent annealing treatment.This particular architecture has favorable transport pathways for both lithium ions and electrons and exhibits an ultrafast chargedischarge capability with high reversible capacities.Furthermore,a well-designed LIC employing the prepared dendrite-structured FeF_(2) as the battery-type cathode and commercialized activated carbon(AC)as supercapacitor-type anode was constructed in an organic electrolyte containing Li ions.The LIC operates at an optimal voltage range of 1.1-3.8 V and shows a maximum high energy density of 152 W h kg^(-1) and a high power density of 4900 W kg^(-1) based on the total mass of cathode and anode.Long-term cycling stability(85%capacity retention after 2000 cycles)was achieved at 1 A g^(-1).This work suggests that the dendrite-structured FeF_(2) is a prime candidate for high-performance LICs and accelerates the development of hybrid ion capacitor devices.
