| Autor: |
Hui Xia, Lingzhe Fang, Teng Zhai, Shuang Li, Qiubo Guo, Jing Xu, Xiaohui Zhu, Xinyi Liu, Liang Xue, Lin Baowei |
| Rok vydání: |
2019 |
| Předmět: |
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| Zdroj: |
Advanced materials (Deerfield Beach, Fla.). 31(24) |
| ISSN: |
1521-4095 |
| Popis: |
Potassium-ion batteries (PIBs) are one of the emerging energy-storage technologies due to the low cost of potassium and theoretically high energy density. However, the development of PIBs is hindered by the poor K+ transport kinetics and the structural instability of the cathode materials during K+ intercalation/deintercalation. In this work, birnessite nanosheet arrays with high K content (K0.77 MnO2 ⋅0.23H2 O) are prepared by "hydrothermal potassiation" as a potential cathode for PIBs, demonstrating ultrahigh reversible specific capacity of about 134 mAh g-1 at a current density of 100 mA g-1 , as well as great rate capability (77 mAh g-1 at 1000 mA g-1 ) and superior cycling stability (80.5% capacity retention after 1000 cycles at 1000 mA g-1 ). With the introduction of adequate K+ ions in the interlayer, the K-birnessite exhibits highly stabilized layered structure with highly reversible structure variation upon K+ intercalation/deintercalation. The practical feasibility of the K-birnessite cathode in PIBs is further demonstrated by constructing full cells with a hard-soft composite carbon anode. This study highlights effective K+ -intercalation for birnessite to achieve superior K-storage performance for PIBs, making it a general strategy for developing high-performance cathodes in rechargeable batteries beyond lithium-ion batteries. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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