Highly reversible potassium-ion intercalation in tungsten disulfide† †Dedicated to Prof. Jin-Shun Huang on the occasion of his 80th birthday. ‡ ‡Electronic supplementary information (ESI) available. See DOI: 10.1039/c8sc04350g
| Autor: | Yilong Pan, Ruding Zhang, Jingze Bao, Chuan-Fu Sun |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
Battery (electricity)
Materials science genetic structures 010405 organic chemistry Potassium Intercalation (chemistry) Tungsten disulfide Inorganic chemistry chemistry.chemical_element General Chemistry 010402 general chemistry Electrochemistry 01 natural sciences 0104 chemical sciences law.invention chemistry.chemical_compound Chemistry chemistry Magazine law Formula unit sense organs Faraday efficiency |
| Zdroj: | Chemical Science |
| ISSN: | 2041-6539 2041-6520 |
| Popis: | 0.62 K+ readily (de)intercalates in WS2 with well-defined voltage plateaus, an intrinsically safe operation potential, and ultrahigh reversibility. Rechargeable potassium-ion batteries (PIBs) show promise beyond Li-ion technology in large-scale electrical-energy storage due to the abundance and low cost of potassium resources. However, the intercalation of large-size K+ generally results in irreversible structural degradation and short lifespan to the hosts, representing a major obstacle. Here, we report a new electrochemical K+-intercalation host, tungsten disulfide (WS2), which can store 0.62 K+ per formula unit with a reversible capacity of 67 mA h g–1 and well-defined voltage plateaus at an intrinsically safe average operation potential of 0.72 V versus K/K+. In situ X-ray diffraction and ex situ electron microscopy revealed the underlying intercalation mechanism, a relatively small cell volume change (37.81%), and high reversibility of this new battery chemistry. Such characteristics impart WS2 with ultrahigh structural stability and a long lifespan, regardless of deep or fast charging. WS2 achieved record-high cyclability among chalcogenides up to 600 cycles with 89.2% capacity retention at 0.3C, and over 1000 cycles with 96.3% capacity retention and an extraordinary average Coulombic efficiency of 99.90% at 2.2C. This intercalation electrochemistry may open up new opportunities for the design of long-cycle-life and high-safety PIBs. |
| Databáze: | OpenAIRE |
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