Three-Dimensional Manganese Oxide@Carbon Networks as Free-Standing, High-Loading Cathodes for High-Performance Zinc-Ion Batteries
Three-Dimensional Manganese Oxide@Carbon Networks as Free-Standing, High-Loading Cathodes for High-Performance Zinc-Ion Batteries
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DOI：
10.1002/sstr.202200316
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发表时间：
2023-01-05
期刊：
影响因子：
15.9
通讯作者：
Carmalt, Claire J.
中科院分区：
文献类型：
--
作者：
Gao, Xuan;Zhang, Chengyi;Carmalt, Claire J.
锌离子电池（ZIB）价格低廉，环境友好，在电网规模的储能系统中具有很大的应用潜力，但其使用受到合适阴极材料可用性的限制。基于MnO 2的阴极正成为一个很有前途的竞争者，因为它具有很好的可用性和安全性，以及稳定的输出电压平台（1.5 V）。改善由低电导率和质量扩散速率引起的基于MnO 2的阴极的缓慢动力学是它们未来在下一代快速充电装置中使用的挑战。在本文中，通过提出具有3D不同厚度碳纳米管（VTCNT）网络的钠插层氧化锰（NMO）作为适当的自立式无粘合剂阴极（NMO/VTCNT）而无需任何热处理来克服上述挑战。首次提出了基于不同直径碳纳米管的网络构建策略，以在实现高质量负载的同时提供高比容量。所制备的阴极的比容量显著提高。所得的自立式无粘合剂阴极实现了优异的容量（在0.2A g（-1）下120次循环后为329 mAh g（-1），在1A g（-1）下200次循环后为225 mAh g（-1））和长期循环稳定性（在2A g（-1）下1000次循环后为158 mAh g（-1））。
Zinc-ion batteries (ZIBs), which are inexpensive and environmentally friendly, have a lot of potential for use in grid-scale energy storage systems, but their use is constrained by the availability of suitable cathode materials. MnO2-based cathodes are emerging as a promising contenders, due to the great availability and safety, as well as the device's stable output voltage platform (1.5 V). Improving the slow kinetics of MnO2-based cathodes caused by low electrical conductivity and mass diffusion rate is a challenge for their future use in next-generation rapid charging devices. Herein, the aforementioned challenges are overcome by proposing a sodium-intercalated manganese oxide (NMO) with 3D varying thinness carbon nanotubes (VTCNTs) networks as appropriate free-standing, binder-free cathodes (NMO/VTCNTs) without any heat treatment. A network construction strategy based on CNTs of different diameters is proposed for the first time to provide high specific capacity while achieving high mass loading. The specific capacity of asprepared cathodes is significantly increased. The resulting free-standing binder-free cathodes achieve excellent capacity (329mAh g(-1) after 120 cycles at 0.2 A g(-1) and 225mAh g(-1) after 200 cycles at 1 A g(-1)) and long-term cycling stability (158mAh g(-1) at 2 A g(-1) after 1000 cycles).