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Concentrated electrolytes stabilize bismuth–potassium batteries

Storing as many as three K-ions per atom, bismuth is a promising anode material for rechargeable potassium-ion batteries that may replace lithium-ion batteries for large-scale electrical energy storage. However, Bi suffers from poor electrochemical cyclability in conventional electrolytes. Here, we...

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Detalles Bibliográficos
Autores principales: Zhang, Ruding, Bao, Jingze, Wang, YuHuang, Sun, Chuan-Fu
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Royal Society of Chemistry 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6062896/
https://www.ncbi.nlm.nih.gov/pubmed/30090306
http://dx.doi.org/10.1039/c8sc01848k
Descripción
Sumario:Storing as many as three K-ions per atom, bismuth is a promising anode material for rechargeable potassium-ion batteries that may replace lithium-ion batteries for large-scale electrical energy storage. However, Bi suffers from poor electrochemical cyclability in conventional electrolytes. Here, we demonstrate that a 5 molar (M) ether-based electrolyte, versus the typical 1 M electrolyte, can effectively passivate the bismuth surface due to elevated reduction resistance. This protection allows a bismuth–carbon anode to simultaneously achieve high specific capacity, electrochemical cyclability and Coulombic efficiency, as well as small potential hysteresis and improved rate capability. We show that at a high electrolyte concentration, the bismuth anode demonstrates excellent cyclability over 600 cycles with 85% capacity retention and an average Coulombic efficiency of 99.35% at 200 mA g(–1). This “concentrated electrolyte” approach provides unexpected new insights to guide the development of long-cycle-life and high-safety potassium-ion batteries.