Cao Kangzhe, Liu Huiqiao, Li Wangyang, Han Qingqing, Zhang Zhang, Huang Kejing, Jing Qiangshan, Jiao Lifang
College of Chemistry and Chemical Engineering, Henan Province Key Laboratory of Utilization of Non-Metallic Mineral in the South of Henan, Xinyang Normal University, Xinyang, 464000, China.
Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), College of Chemistry, Nankai University, Tianjin, 300071, China.
Small. 2019 Sep;15(36):e1901775. doi: 10.1002/smll.201901775. Epub 2019 Jul 24.
Potassium-ion batteries (KIBs) are promising alternatives to lithium-ion batteries because of the abundance and low cost of K. However, an important challenge faced by KIBs is the search for high-capacity materials that can hold large-diameter K ions. Herein, copper oxide (CuO) nanoplates are synthesized as high-performance anode materials for KIBs. CuO nanoplates with a thickness of ≈20 nm afford a large electrode-electrolyte contact interface and short K ion diffusion distance. As a consequence, a reversible capacity of 342.5 mAh g is delivered by the as-prepared CuO nanoplate electrode at 0.2 A g . Even after 100 cycles at a high current density of 1.0 A g , the capacity of the electrode remains over 206 mAh g , which is among the best values for KIB anodes reported in the literature. Moreover, a conversion reaction occurs at the CuO anode. Cu nanoparticles form during the first potassiation process and reoxidize to Cu O during the depotassiation process. Thereafter, the conversion reaction proceeds between the as-formed Cu O and Cu, yielding a reversible theoretical capacity of 374 mAh g . Considering their low cost, easy preparation, and environmental benignity, CuO nanoplates are promising KIB anode materials.
钾离子电池（KIBs）因其钾资源丰富且成本低，是锂离子电池颇具前景的替代品。然而，KIBs面临的一个重要挑战是寻找能够容纳大直径钾离子的高容量材料。在此，合成了氧化铜（CuO）纳米片作为KIBs的高性能负极材料。厚度约为20nm的CuO纳米片提供了较大的电极 - 电解质接触界面和较短的钾离子扩散距离。因此，所制备的CuO纳米片电极在0.2A/g电流密度下可逆容量为342.5mAh/g。即使在1.0A/g的高电流密度下循环100次后，电极容量仍保持在206mAh/g以上，这是文献报道的KIB负极的最佳值之一。此外，在CuO负极发生了转化反应。在首次钾化过程中形成铜纳米颗粒，并在脱钾过程中重新氧化为Cu₂O。此后，在形成的Cu₂O和Cu之间进行转化反应，产生374mAh/g的可逆理论容量。考虑到其低成本、易于制备和环境友好性，CuO纳米片是很有前景的KIB负极材料。
