2D Phosphorene-Decorated Ni-Rich Layered Cathodes for High-Power and High-Energy Li-Ion Batteries

Abstract

To meet the demands of high-energy lithium-ion batteries (LIBs), cathodes must achieve high mass loading and low carbon content without compromising rate capability or cycling stability. However, the intrinsically low electronic conductivity of conventional surface coatings limits their effectiveness under high mass loading and low carbon content conditions. Here, a surface modification strategy leveraging conductive and chemically stable 2D phosphorene (2DP), electrochemically exfoliated from black phosphorus, is presented to modify the surface of Li[Ni0.8Co0.1Mn0.1]O2 (NCM811) cathodes. The 2DP-decorated NCM811 (2DP-NCM811) delivers a high discharge capacity of 209.7 mAh g-1 at 30 mA g-1 and maintains 183.2 mAh g-1 at 500 mA g-1 under practical conditions (18 mg cm-2 cathode loading, 1 wt.% carbon). Compared to bare and phosphate-decorated counterparts, 2DP-NCM811 exhibits enhanced power capability. It also shows improved cycling stability with 82.7% capacity retention after 100 cycles, outperforming bare NCM811 (73.8%) and phosphate-decorated NCM811 (80.1%). Operando X-ray diffraction and ex situ transmission electron microscopy confirm that the application of 2DP effectively suppresses structural degradation. This study demonstrates a surface engineering strategy that addresses both structural instability and electronic limitations by integrating a conductive and chemically stable 2D material, offering a scalable route toward high-performance LIB cathodes.