High capacity potassium-ion battery anodes based on black phosphorus

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Materials for energy and sustainability, 2017, Vol.5 (45), p.23506-23512
• Main Authors: Sultana, Irin, Rahman, Md Mokhlesur, Ramireddy, Thrinathreddy, Chen, Ying, Glushenkov, Alexey M.
• Format: Article
• Language: English
• Subjects: Anodes; Batteries; Data processing; Electrochemistry; Electrode materials; Energy storage; Feasibility studies; Graphite; Gravimetry; High voltage; Lithium; Lithium-ion batteries; Nanocomposites; Phosphorus; Potassium; Potassium channels (voltage-gated); Rechargeable batteries; Sodium; Storage batteries; X-ray diffraction
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/C7TA02483E

Potassium-ion batteries are a new class of high voltage electrochemical energy storage cells that may potentially complement or replace lithium-ion batteries in many applications. Graphite is considered as a prospective anode material for these batteries but its demonstrated capacity is only 270 mA h g −1 . This manuscript studies a novel type of nanocomposite anodes based on black phosphorus as their main active component, with a much higher capacity in potassium-ion batteries. These anode materials are able to deliver a first cycle capacity as high as 617 mA h g −1 , more than twice the capacity of graphite in potassium cells. Quick depotassiation is achievable in the electrodes under certain conditions. Based on the data of X-ray diffraction analysis, it is proposed that black phosphorus operates via an alloying–dealloying mechanism with potassium and the end product of the electrochemical transformation is a KP alloy (implying a theoretical capacity of 843 mA h g −1 for phosphorus in potassium cells). This work emphasizes the feasibility of potassium-ion battery anode materials with high gravimetric capacities, comparable with those of high capacity anode materials for lithium-ion and sodium-ion batteries.