首页|PVA-regulated construction of 3D rGO-hosted Na3V2(PO4)2F3 for fast and stable sodium storage

PVA-regulated construction of 3D rGO-hosted Na3V2(PO4)2F3 for fast and stable sodium storage

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Na3V2(PO4)2F3(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 dis-cover 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 rGO 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 mAh/g and 113 mAh/g at 1C and 10C,respectively,and 103 mAh/g after 700 cycles 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 tempera-ture 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 elec-trode and commercial hard carbon as the negative electrode,a sodium-ion full battery has been assem-bled with about 110 mAh/g at 1C for 300 cycles,corresponding to an energy density of 291 Wh kg-1.The construction of 3D rGO housing as a conductive support offers an effective strategy for high-rate,long cycle life and high safety sodium-ion battery cathodes.

Sodium-ion batteryPolyanionic compoundReduced graphene oxide3D carbon layersNa3V2(PO4)2F3

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

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School of Materials and Energy,University of Electronic Science and Technology of China,Chengdu 610054,Sichuan,China

Medical and Pharmaceutical College,Chongqing 401331,China

Institute for Advanced Study,Chengdu University,Chengdu 610054,Sichuan,China

Shenzhen Institute for Advanced Study,University of Electronic Science and Technology of China,Shenzhen 518000,Guangdong,China

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2024

10.1016/j.jechem.2024.07.032

能源化学
中国科学院大连化学物理研究所 中国科学院成都有机化学研究所

能源化学

CSTPCDEI
影响因子：0.654
ISSN：2095-4956
年,卷(期)：2024.99(12)