Yu Xiang,Qingping Li,Xijun Wei,Xiaoyan Li,Qiaoji Zheng,Yu Huo,Dunmin Lin
Reasonable design and synthesis of anode materials with high capacity, excellent rate capability and good cycling stability is vital for the pragmatic application of sodium-ion batteries (SIBs). Transition metal chalcogenides possess immense potential on account of their distinguished redox reversibility and high theoretical specific capacity. Herein, the hollow metal sulfide/metal selenide (NiS 2 /NiSe 2 ) heteroboxes with rich phase boundaries have been manufactured as anode for SIBs. The lattice distortion and charge redistribution at the phase boundary of the as-prepared NiS 2 /NiSe 2 heteroboxes can expose more active sites, which is profitable to the adsorption of Na + and accelerate the sodium storage kinetics process, and the unique hollow porous structure is conducive to buffering the volume expansion and can facilitate the penetration of electrolyte during the repeated Na + de-intercalation process. By virtue of these advantages, the NiS 2 /NiSe 2 heteroboxes delivers a good rate capability, where the average capacity at 10 A g - 1 in comparison with 0.1 A g - 1 is 64.3%. Otherwise, it exhibits an ultralong reversible capacity of 292 mA h g - 1 after 2000 cycles at 10 A g - 1 with only 0.0125% average capacity decay per cycle. The rational construction of phase boundary with unique structure in this article has guiding significance for the manufacture of progressive SIBs anode materials.
Yi Yu,Wenbin Luo,Zhen Zhang,Ying Feng,Jian Li,Mingyu Zheng,Zisheng Chao,JinCheng Fan
Aluminum batteries (ABs) have recently become a type of battery technology that has attracted much attention due to their advantages such as abundant resources and high theoretical capacity. However, the development of ABs is limited by the inherent characteristics of the positive electrode materials, so finding high-performance positive electrode materials has become a top priority in research. Transition metal sulfides/selenides, as positive electrode materials for ABs, offer notable benefits such as high specific capacity and long cycle life, showing great application potential. In this study, a nanoscale porous dodecahedral NiS2/NiSe2 heterojunction was designed and prepared for an ABs positive electrode. The unique heterojunction structure generates a built-in electric field, which facilitates the transport of electrons and ions and improves the reaction kinetics. Nanoparticles can provide a larger specific surface area, while the porous structure supports buffering volume expansion and promotes electrolyte infiltration, thereby improving the electrochemical performance. Experimental results show that the NiS2/NiSe2 heterojunction exhibits a notable initial capacity of 375.5 mAh/g within the voltage range of 0.01–2.3 V, and it can still maintain 81.1 mAh/g after 400 cycles. This research provides ideas for developing a high-performance positive electrode for ABs.
Bo Yuan,Jianxun Zhao,Wanqiang Liu,Heng Liu,Peng Chen,Lianshan Sun,Xin Guo,Xinwei Wang,Weixuan Zhang,Rui Zhang,Fang Wang
The introduction of heterostructure in the cathode material of Li-S battery is an effective method to improve the redox reaction kinetics and suppress the shuttle effect of polysulfide . A metal sulfide/metal selenide (NiS 2 /NiSe 2 ) heterostructure with hollow tetrahedral structure is prepared as a sulfur host of lithium-sulfur batteries. The prepared NiS 2 /NiSe 2 heterostructure exhibits efficient charge transfer at the heterojunction interface, thereby enhancing catalytic activity for redox reactions of polysulfides and facilitating their rapid conversion. Moreover, the unique hollow tetrahedral structure, along with abundant surface pores, enables high sulfur loading capacity, providing abundant electrochemical reaction sites to enhance sulfur utilization efficiency. The results demonstrate that the NiS 2 /NiSe 2 heterostructure material exhibits a remarkable initial capacity of 1338.9 mAh/g at 0.2 C, along with exceptional cycling stability (maintaining a capacity of 517.6 mAh/g after 200 cycles at 0.2 C, with only a negligible decay rate of 0.3% per cycle, retaining a capacity of 462.6 mAh/g after 500 cycles at 1 C, with an insignificant decay rate of merely 0.12% per cycle). The facile preparation of this NiS 2 /NiSe 2 heterostructure not only enables the realization of lithium-sulfur batteries with exceptional capacity, but also opens up broader avenues for exploring high-performance heterogeneous materials .
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