Peering into few-layer black phosphorus nanosheets: from preparation to battery applications

Abstract

Few-layer black phosphorus (FLBP) nanosheets feature high charge storage capacity, large surface area, considerable mechanical flexibility, high carrier mobility and adjustable intrinsic band gap, allowing wide applications in electrochemical storage and conversion. This article presents a review on the preparation of FLBP materials and their applications in rechargeable batteries, including alkali metal batteries. Top-down and bottom-up synthetic strategies of FLBP are overviewed with examples of mechanical, liquid-phase and electrochemical exfoliation routes and chemical vapour and pulsed laser deposition. The electrochemical properties, structure-performance relationship and electrode mechanisms of FLBP are demonstrated as anode materials for storage of lithium, sodium and potassium ions. Issues including huge volume expansion and structural instability are discussed, along with solving strategies such as composing with nanostructured carbon, MXene, conductive polymer and transition metal oxides. Furthermore, the remaining challenges and future perspectives for the electrochemical use of FLBP are highlighted.