PVA-regulated construction of 3D rGO-hosted Na_(3)V_(2)(PO_(4))_(2)F_(3) for fast and stable sodium storage  

作　　者：Shilong Xu Ying Zhu Xinyan Li Yamei Wang Dong Yan Xiaobin Niu Jingxia Jiang Rui Wu Jun Song Chen 

机构地区：[1]School of Materials and Energy,University of Electronic Science and Technology of China,Chengdu 610054,Sichuan,China [2]Medical and Pharmaceutical College,Chongqing 401331,China [3]Institute for Advanced Study,Chengdu University,Chengdu 610054,Sichuan,China [4]Shenzhen Institute for Advanced Study, University of Electronic Science and Technology of China,Shenzhen 518000,Guangdong,Chin

出　　处：《Journal of Energy Chemistry》2024年第12期100-109,共10页能源化学（英文版）

基　　金：financially supported by the National Natural Science Foundation of China (No. 52372176);Guangdong Basic and Applied Basic Research Foundation (No. 2024A1515011517)。

摘　　要：Na_(3)V_(2)(PO_(4))_(2)F_(3)(NVPF) is shown to be an attractive cathode material for sodium storage due to its high theoretical capacity and suitable working voltage.However,its low electronic conductivity and poor cycling stability have to be addressed in order for enhanced high-rate performance and cycle life.Herein,we have prepared a 3D reduced graphene oxide (rGO) host-supported NVPF nanocuboids.We discover that polyvinyl alcohol (PVA) serves as an important structural directing agent that bridges between NVPF and rGO through the hydrogen bonding,and thus regulates the formation of the 3D r GO framework with NVPF nanocuboids embedded inside (NVPF@C@rGO).With such a unique construction,NVPF@C@rGO exhibits excellent cycling stability and rate performance for sodium storage,showing high reversible capacities of 121 m Ah/g and 113 mAh/g at 1C and 10C,respectively,and 103 mAh/g after 700cycles at 50C with 98.3%retention.Even at an extremely high current of 100C,it also delivers a reversible capacity of 64 mAh/g,surpassing the performance of many recently reported NVPF-based electrodes.Cyclic voltammetry (CV) and galvanostatic intermittent titration technique (GITT) data confirm the much better kinetic properties of NVPF@C@rGO electrode than the control samples of NVPF@rGO and pure NVPF.In-situ XRD results reveal that the 3D rGO housing can effectively suppress the lattice variation of NVPF,with a maximum volume change of only 1.84%during cycling.Moreover,the in-situ temperature sensing reveals the more stable working temperature of NVPF@C@rGO compared to phase-pure NVPF,suggesting a higher temperature safety of the electrode.Using NVPF@C@rGO as the positive electrode and commercial hard carbon as the negative electrode,a sodium-ion full battery has been assembled with about 110 m Ah/g at 1C for 300 cycles,corresponding to an energy density of 291 Wh kg^(-1).The construction of 3D r GO housing as a conductive support offers an effective strategy for high-rate,long cycle life and high safety sodium-ion battery catho

关 键 词：Sodium-ion battery Polyanionic compound Reduced graphene oxide 3D carbon layers Na_(3)V_(2)(PO_(4))_(2)F_(3) 

分 类 号：TM912[电气工程—电力电子与电力传动] O646[理学—物理化学]