Sodium superionic conductors(NASICONs)have attracted enormous attention owing to their excellent ionic diffusion and structural stability.However,the high cost of vanadium,limited capacity due to fewer redox reactions...Sodium superionic conductors(NASICONs)have attracted enormous attention owing to their excellent ionic diffusion and structural stability.However,the high cost of vanadium,limited capacity due to fewer redox reactions,and low electronic conductivity restrict their practical application.Herein,we designed Na_(3.5)V_(0.5)Mn_(0.5)Fe_(0.5)Ti_(0.5)(PO_(4))3 (NVMFTP)medium entropy NASICON with multi-electron reactions as a fast sodium storage cathode for sodium-ion batteries(SIBs).The incorporation of Fe,Mn and Ti not only reduces the cost but also activates multi-redox reactions of V^(2+)/V^(3+),Ti^(3+)/Ti^(4+),Fe^(2+)/Fe^(3+),V^(3+)/V^(4+),Mn^(2+)/Mn^(3+),V^(4+)/V^(5+).Owing to distinctive structural design with medium entropy,the NVMFTP delivered 168 mAh·g^(−1) at 0.5C with a remarkable rate capability of 93.51 mAh·g^(−1) at 60C and steady long-term cycling performance till 5000 cycles.More importantly,NVMFTP takes only 11 min to achieve 80%SOC at 5C.The in-situ and ex-situ X-ray diffraction(XRD)further demonstrate reversible multi-electron reaction mechanisms of slow charging and fast charging.NVMFTP/HC full cell shows 110 mAh·g^(−1) capacity and 208 Wh·kg^(−1) energy density.This study will provide comprehensive insight into developing low-cost,cutting-edge materials for SIBs.展开更多
Compared to traditional liquid electrolyte batteries,solid metal batteries offer advantages such as a wide operating temperature range,high energy density,and improved safety,making them a promising energy storage tec...Compared to traditional liquid electrolyte batteries,solid metal batteries offer advantages such as a wide operating temperature range,high energy density,and improved safety,making them a promising energy storage technology.Solid electrolytes,as the core components of solid‐state batteries,are key factors in advancing solid‐state battery technology.Among various solid electrolytes,Na super ionic conductor(NASICON)‐type solid electrolytes exhibit high ionic conductivity(10−3 S·cm−1),a wide electrochemical window,and good thermal stability,providing room for the development of high energy‐density solid metal batteries.Since the discovery of NASICON‐type solid electrolytes in 1976,interest in their use in all‐solid‐state battery development has grown significantly.In this review,we comprehensively analyze the common features of NASICON lithium‐ion conductors and NASICON sodium‐ion conductors,review the historical development of NASICON‐type solid electrolytes,systematically summarize the transport mechanisms of metal cations in NASICON‐type solid electrolytes,discuss the latest strategies for enhancing ionic conductivity,elaborate on the latest methods for improving mechanical stability and interface stability,and point out the requirements of high energy density devices for NASICON‐type solid electrolytes as well as three types of in situ characterization techniques for interfaces.Finally,we highlight the challenges and potential solutions for the future development of NASICON‐type solid electrolytes and solid‐state metal batteries.展开更多
基金supported by the National Natural Science Foundation of China(Nos.52027801 and 92263203)the National Key R&D Program of China(Nos.2022YFA1203902 and 2022YFA1200093)and the China-Germany Collaboration Project(No.M-0199)。
文摘Sodium superionic conductors(NASICONs)have attracted enormous attention owing to their excellent ionic diffusion and structural stability.However,the high cost of vanadium,limited capacity due to fewer redox reactions,and low electronic conductivity restrict their practical application.Herein,we designed Na_(3.5)V_(0.5)Mn_(0.5)Fe_(0.5)Ti_(0.5)(PO_(4))3 (NVMFTP)medium entropy NASICON with multi-electron reactions as a fast sodium storage cathode for sodium-ion batteries(SIBs).The incorporation of Fe,Mn and Ti not only reduces the cost but also activates multi-redox reactions of V^(2+)/V^(3+),Ti^(3+)/Ti^(4+),Fe^(2+)/Fe^(3+),V^(3+)/V^(4+),Mn^(2+)/Mn^(3+),V^(4+)/V^(5+).Owing to distinctive structural design with medium entropy,the NVMFTP delivered 168 mAh·g^(−1) at 0.5C with a remarkable rate capability of 93.51 mAh·g^(−1) at 60C and steady long-term cycling performance till 5000 cycles.More importantly,NVMFTP takes only 11 min to achieve 80%SOC at 5C.The in-situ and ex-situ X-ray diffraction(XRD)further demonstrate reversible multi-electron reaction mechanisms of slow charging and fast charging.NVMFTP/HC full cell shows 110 mAh·g^(−1) capacity and 208 Wh·kg^(−1) energy density.This study will provide comprehensive insight into developing low-cost,cutting-edge materials for SIBs.
基金supported by the National Natural Science Foundation of China(No.52472137)the Talent Introduction Research Project of Hebei University(No.521100224231)the Shanghai Magnolia Talent Plan Pujiang Project(23PJ1415600)。
文摘Compared to traditional liquid electrolyte batteries,solid metal batteries offer advantages such as a wide operating temperature range,high energy density,and improved safety,making them a promising energy storage technology.Solid electrolytes,as the core components of solid‐state batteries,are key factors in advancing solid‐state battery technology.Among various solid electrolytes,Na super ionic conductor(NASICON)‐type solid electrolytes exhibit high ionic conductivity(10−3 S·cm−1),a wide electrochemical window,and good thermal stability,providing room for the development of high energy‐density solid metal batteries.Since the discovery of NASICON‐type solid electrolytes in 1976,interest in their use in all‐solid‐state battery development has grown significantly.In this review,we comprehensively analyze the common features of NASICON lithium‐ion conductors and NASICON sodium‐ion conductors,review the historical development of NASICON‐type solid electrolytes,systematically summarize the transport mechanisms of metal cations in NASICON‐type solid electrolytes,discuss the latest strategies for enhancing ionic conductivity,elaborate on the latest methods for improving mechanical stability and interface stability,and point out the requirements of high energy density devices for NASICON‐type solid electrolytes as well as three types of in situ characterization techniques for interfaces.Finally,we highlight the challenges and potential solutions for the future development of NASICON‐type solid electrolytes and solid‐state metal batteries.
文摘以Li_2CO_3、ZrO_2、Er_2O_3、(NH_4)_2HPO_4为初始原料,采用传统的固相法合成了Li Zr_2(PO_4)_3基NASICON型固态电解质材料Li_(1+x)Er_xZr_(2-x)(PO_4)_3(x=0~0.2)。通过无压烧结和放电等离子烧结法(SPS)烧结得到致密的电解质片,采用无压烧结过程中在样品中加入少许的PVA使得样品烧结致密。利用XRD、SEM、EIS分别测得样品的结构、形貌以及电性能。结果表明:通过SPS烧结的样品致密度可以达到92.6%。使用SPS烧结后的样品Li1.15Er0.15Zr1.85(PO_4)_3在常温下的晶粒和总电导率分别为2.2×10^(-4)和8.8×10^(-6) S·cm^(-1)。样品的激活能为0.36 e V。
