Uniform P2-K<sub>0.6</sub>CoO<sub>2</sub> Microcubes as a High-Energy Cathode Material for Potassium-Ion Batteries.

Zhang, Zhuangzhuang; Hu, Qiao; Liao, Jiaying; Xu, Yifan; Duan, Liping; Tian, Ruiqi; Du, Yichen; Shen, Jian et al. · Nano Lett · 2023

basic_science · Level V

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Abstract

Layered transition-metal (TM) oxides have drawn ever-growing interest as positive electrode materials in potassium-ion batteries (PIBs). Nevertheless, the practical implementation of these positive electrode materials is seriously hampered by their inferior cyclic property and rate performance. Reported here is a self-templating strategy to prepare homogeneous P2-K<sub>0.6</sub>CoO<sub>2</sub> (KCO) microcubes. Benefiting from the unusual microcube architecture, the interface between the electrolyte and the active material is considerably diminished. As a result, the KCO microcubes manifest boosted electrochemical properties for potassium storage including large reversible capacity (87.2 mAh g<sup>-1</sup> under 20 mA g<sup>-1</sup>), superior rate performance, and ultralong cyclic steady (an improved capacity retention of 86.9% under 40 mA g<sup>-1</sup> after 1000 cycles). More importantly, the fabrication approach can be effectively extended to prepare other layered TM oxide (P3-K<sub>0.5</sub>MnO<sub>2</sub>, P3-K<sub>0.5</sub>Mn<sub>0.8</sub>Fe<sub>0.2</sub>O<sub>2</sub>, P2-K<sub>0.6</sub>Co<sub>0.67</sub>Mn<sub>0.33</sub>O<sub>2</sub>, and P2-K<sub>0.6</sub>Co<sub>0.66</sub>Mn<sub>0.17</sub>Ni<sub>0.17</sub>O<sub>2</sub>) microcubes and nonlayered TM oxide (KFeO<sub>2</sub>) microcubes.