Key Laboratory of Hebei Province on Scale-span Intelligent Equipment Technology, Tianjin Key Laboratory of Power Transmission and Safety Technology for New Energy Vehicles, and School of Mechanical Engineering, Hebei University of Technology, Tianjin 300401, China.
The Green Aerotechnics Research Institute of Chongqing Jiaotong University, Chongqing 401120, China.
J Colloid Interface Sci. 2023 May 15;638:274-280. doi: 10.1016/j.jcis.2023.01.136. Epub 2023 Feb 1.
Nickel sulfides, as promising candidate for aqueous rechargeable battery, have aroused broad attention on account of abundant natural resources, rich phases, moderate price and high theoretical capacity. Nevertheless, tremendous volume expansion during repeated charging-discharging procedure leads to the poor rate capability and cycling stability of nickel sulfide electrodes. Therefore, in this work, core-shell NiS@C encapsulated by thin hydrothermal carbon (HC) layer (NiS@C/HC) has been designed and prepared without any surfactants or templates assistance, which avoid tedious process and shorten preparation cycle greatly. When matched with the treated iron powder (TIP) electrode to form NiS@C/HC//TIP aqueous rechargeable battery, the NiS@C/HC//TIP battery exhibits a high discharge capacity of 205.1 mAh g at 1 A g, remarkable rate ability (176.4 mAh g at 5 A g, about 86% capacity conversation) and superiorly durable stability (80.8 % capacity retention after 10,000 cycles at ultra-high current density of 15 A g). The outstanding high-rate capability and cycling stability for aqueous rechargeable battery can be ascribed to the distinct cowpea-like architecture and intrinsic properties of NiS@C/HC. Specifically, the interior porous carbon provides a space to tolerate the volume expansion of the NiS nanoparticles and prevent NiS nanoparticles from aggregation, guaranteeing its high-rate capability. Meanwhile, the exterior HC layer is conducive to improve the electric conductivity to facilitate the electrons transfer and promote the mechanical strength of the whole active materials, ensuring its robust cycling stability.
硫化镍作为一种有前途的水系可充电电池候选材料，由于其丰富的自然资源、丰富的相态、适中的价格和高的理论容量而引起了广泛的关注。然而，在反复的充放电过程中会发生巨大的体积膨胀，这导致了硫化镍电极的差的倍率性能和循环稳定性。因此，在这项工作中，设计并制备了一种没有使用任何表面活性剂或模板的核壳结构的 NiS@C 纳米复合材料，其内核为 NiS 纳米颗粒，外壳为薄的水热碳（HC）层（NiS@C/HC）。这种设计避免了繁琐的过程，大大缩短了制备周期。当与经过处理的铁粉（TIP）电极匹配形成 NiS@C/HC//TIP 水系可充电电池时，NiS@C/HC//TIP 电池表现出了高的放电容量（在 1 A g 的电流密度下为 205.1 mAh g），显著的倍率性能（在 5 A g 的电流密度下为 176.4 mAh g，约为 86%的容量保持率）和优越的耐用稳定性（在超高电流密度 15 A g 下循环 10000 次后，容量保持率为 80.8%）。这种水系可充电电池的突出的高倍率性能和循环稳定性可归因于独特的豇豆花状结构和 NiS@C/HC 的固有特性。具体来说，内部多孔碳提供了一个空间来容纳 NiS 纳米颗粒的体积膨胀，并防止 NiS 纳米颗粒的聚集，保证了其高倍率性能。同时，外部的 HC 层有利于提高电导率，促进电子转移，并增强整个活性材料的机械强度，保证了其稳定的循环性能。
