Improving the electrochemical performance of Na3V2(PO4)3 cathode in sodium ion batteries through Ce/V substitution based on rational design and synthesis optimization. (1st June 2017)

• Record Type: Journal Article
• Authors: Zheng, Qiong; Yi, Hongming; Liu, Wanqiu; Li, Xianfeng; Zhang, Huamin
• Is Part Of: Electrochimica acta. Volume 238(2017)
• Page Start: 288
• Page End: 297
• Publication Date: 2017-06-01
• Subjects: Na3V2(PO4)3 -- Ce/V substitution -- Sodium ion batteries -- Bulk phase characteristic -- High mass loading; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2017.04.029
• Languages: English
• ISSNs: 0013-4686

Abstract

Graphical abstract: Highlights: Ce/V substitution is proposed to improve bulk phase characteristic of Na3 V2 (PO4 )3 . The 2 mol % Ce-doping NVP delivered a discharge capacity of 118 mAh g ‐1 at 0.5C. The discharge capacity of Na3V1.96Ce0.04(PO4)3 can achieve over 100 mAh g ‐1 at 40C. The capacity retention of Na3V1.96Ce0.04(PO4)3 keeps ∼99% at 10C after 100 cycles. High mass load of Na3V1.96Ce0.04(PO4)3 is verified with improved rate performance. Abstract: Ce atom is employed to partially substitute V site in Na3 V2 (PO4 )3 (NVP) crystal structure to improve its bulk phase characteristic. The effect of Ce substitution on the crystal structure, morphology, electrochemical performance and kinetic property of NVP is investigated based on rational design and synthesis optimization. The results indicates that the moderate Ce substitution in the NVP crystal can effectively enhance the bulk phase electronic conductivity and Na + mobility, which excludes the carbon coating effect for the first time. And Na3 V1.96 Ce0.04 (PO4 )3 /C shows the best electrochemical performances among the Na3 V2-x Cex (PO4 )3 /C (x = 0, 0.02, 0.04, 0.06 and 0.1) samples. It delivers a discharge capacity of 118 mAh g −1 at 0.2C and more than 100 mAh g −1 even at 40C, which is currently the highest level by metallic ion doping. After 100 cycles, the capacity retention of Na3 V1.96 Ce0.04 (PO4 )3 /C keeps higher than 99% at 10C. The outstanding performance of the moderate Ce-doping sample is verified further by the electrochemical performance test of the samples with high mass loading, which is highly beneficial to industrial applications of Na3 V2 (PO4 )3 cathode for high performance sodium ion batteries.