Nickel and cobalt Co-substituted spinel ZnMn2O4@N-rGO for increased capacity and stability as a cathode material for rechargeable aqueous zinc-ion battery

• Published in: Electrochimica acta Vol. 331; p. 135296
• Main Authors: Tao, Yayuan, Li, Zhi, Tang, Linbin, Pu, Xiaoming, Cao, Tong, Cheng, Danhong, Xu, Qunjie, Liu, Haimei, Wang, YongGang, Xia, Yongyao
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 20.01.2020; Elsevier BV
• Subjects: Aqueous zinc ion battery; Cathode; Cathodes; Co-substituting; Cobalt; Competitive materials; Electrochemical analysis; Electrode materials; Energy storage; Graphene; Insertion; Intercalation; Jahn-Teller effect; Nanoparticles; Nickel; Rechargeable batteries; Spinel; Spinel ZnMn2O4; Stability; Storage batteries; Substitutes; Zinc compounds; Spinel ZnMn2O4; Cathode; Co-substituting; Aqueous zinc ion battery
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2019.135296

Rechargeable aqueous zinc-ion batteries (ZIBs) are possible future replacements for large-scale energy storage devices because of their safety, low cost, and abundance of materials. Finding a competitive cathode material suitable for zinc-ion insertion/de-insertion, needed to achieve high reversible capacity and long cycle stability, is one of the most important and arduous challenges. For the first time, nickel and cobalt co-substituted spinel ZnMn2O4 nanoparticles, homogeneously loaded onto N-doped reduced graphene oxide (ZnNixCoyMn2-x-yO4@N-rGO), were synthesised through a one-step hydrothermal method and applied as a cathode material to accommodate the intercalation of zinc ions. The as-prepared ZnNixCoyMn2-x-yO4@N-rGO displayed excellent electrochemical performance, with a reversible capacity of 95.4 mA h g−1, achieved at 1000 mA g−1 after 900 cycles, and a capacity retention ratio of 79%. When the current density increased from 10 mA g−1 to 1500 mA g−1, high capacity (200.5 mA h g−1 to 93.5 mA h g−1) was achieved, which was much higher than that of ZMO@N-rGO without nickel and cobalt co-substituting (184 mA h g−1 to 59.2 mA h g−1), demonstrating excellent rate performance. These excellent electrochemical properties are attributed to the co-substituting of nickel and cobalt elements, which is an effective approach to promote Zn2+ de-intercalation and to stabilize the spinel structure in order to suppress the Jahn-Teller distortion of Mn3+. Therefore, nickel and cobalt co-substituting of spinel ZnMn2O4@N-rGO with a stable structure opens up new possibilities for large-scale application of rechargeable, aqueous ZIBs. [Display omitted] •Nickel and cobalt co-substituted spinel ZnMn2O4 nanoparticles were synthesised•The ultrafine ZnNi0.39Co0.59Mn0.98O4 loaded onto N-doped reduced graphene oxide.•The ZnNi0.39Co0.59Mn0.98O4@N-rGO exhibited excellent performance as a cathode for SIBs.•Nickel and cobalt co-substituting stabilized the spinel structure.•The N-doped graphene network ensured highly electronic conductivity.