Engineering yolk–shell P-doped NiS2/C spheres via a MOF-template for high-performance sodium-ion batteries. Issue 17 (22nd April 2020)

• Record Type: Journal Article
• Authors: Wang, Liqin; Han, Zhanli; Zhao, Quanqing; Yao, Xiuyun; Zhu, Youqi; Ma, Xilan; Wu, Shide; Cao, Chuanbao
• Is Part Of: Journal of materials chemistry. Volume 8:Issue 17(2020)
• Page Start: 8612
• Page End: 8619
• Publication Date: 2020-04-22
• Subjects: Materials -- Research -- Periodicals; Chemistry, Analytic -- Periodicals; Environmental sciences -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d0ta02568b
• Languages: English
• ISSNs: 2050-7488

Abstract

Abstract : The stable yolk–shell P-doped NiS2 /C spheres were successfully fabricated via MOFs template, and first adopted phytic acid as P source. Due to the unique framework and synergistic effect, P-doped NiS2 /C sample displayed high sodium storage capacity. Abstract : Transition metal sulfides generally demonstrate unsatisfactory capacity and a limited rate capability that still restrict their application for sodium-ion batteries. Herein, yolk–shell P-doped NiS2 /C spheres were synthesized via a Ni-MOF template with phytic acid acting as a P source to significantly enhance the sulfide's sodium storage property. The yolk–shell P-doped NiS2 /C spheres exhibited an ultrahigh initial discharge and charge capacities of 3546.7 and 2622.9 mA h g −1 with 72.9% coulombic efficiency, and maintained a relatively high reversible capacity of 1113.5 mA h g −1 at 0.1 A g −1 after 20 cycles. Electrochemical measurements further revealed that the yolk–shell P-doped NiS2 /C spheres could also deliver a good rate capability and stable long-term cycling performance with 766.8 mA h g −1 reversible capacity at 0.5 A g −1 after 400 cycles. The satisfactory electrochemical results could be ascribed to the confinement and synergistic effect from the robust yolk–shell framework and heteroatom P doping. Therefore, it was demonstrated that morphology tuning and heteroatom P doping can serve as effective strategies to significantly improve the electrochemical properties of transition metal sulfides for sodium-ion batteries.