Multiple anionic Ni(SO4)(0.3)(OH)(1.4) nanobelts/reduced graphene oxide enabled by enhanced multielectron reactions with superior lithium storage capacity

The multielectron reaction materials for lithium-ion batteries are interesting charge storage hosts for next-generation high-energy-density anodes. As a class of multiple-anion transition metal compounds (MATMCs), the layered Nickel hydroxide sulfate (NiSH) nanobelts integrate positive-charged cations and intercalated anions, can be expected to construct the advanced high-energy-density materials, but have not yet reported. Herein, the layered NiSH nanobelts grafting on the 3D porous reduced Graphene oxide (rGO) nanosheets were fabricated for the first time as the negative electrode of lithium-ion battery (denoted as NiSH@rGO) by a one-pot hydrothermal approach. As expected, the NiSH@rGO composite delivers a superior initial discharge capacity (1060 mAh g(-1) at 200 mA g(-1) after 230 cycles) and an exceptional rate capacity (991 mA g(-1) at 2000 mA g(-1)). Through in-situ XRD, ex-situ SEM and TEM, we showed that the outstanding performance of NiSH@rGO anode originate from multielectron reaction mechanism and prominent structural, which render expose more active sites for charge storage, increase the surface wettability of anode, accelerate electron/ion diffusion and ensure the stability of the structure. Above that, it showed excellent lithium storage capacity and high-rate performance. Furthermore, a full cell composed of the NiSH@rGO anode and LiFePO4 cathode displays an impressive capacitance and low-capacity decay rate. Our findings fundamentally and experimentally provide insights into the multi-anionic compounds for markedly enhancing the performance of the multi-electron anodes for advanced high-capacity lithium-ion battery.