Single‐Layer‐Particle Electrode Design for Practical Fast‐Charging Lithium‐Ion Batteries

Abstract

Efforts to enable fast charging and high energy density lithium-ion batteries (LIBs) are hampered by the trade-off nature of the traditional electrode design: increasing the areal capacity usually comes with sacrificing the fast charge transfer. Here a single-layer chunky particle electrode design is reported, where red-phosphorus active material is embedded in nanochannels of vertically aligned graphene (red-P/VAG) assemblies. Such an electrode design addresses the sluggish charge transfer stemming from the high tortuosity and inner particle/electrode resistance of traditional electrode architectures consisting of randomly stacked active particles. The vertical ion-transport nanochannels and electron-transfer conductive nanowalls of graphene confine the direction of charge transfer to minimize the transfer distance, and the incomplete filling of nanochannels in the red-P/VAG composite buffers volume change locally, thus avoiding the variation of electrodes thickness during cycling. The single-layer chunky particle electrode displays a high areal capacity (5.6 mAh cm^-2 ), which is the highest among the reported fast-charging battery chemistries. Paired with a high-loading LiNi_0.6 Co_0.2 Mn_0.2 O₂ (NCM622) cathode, a pouch cell shows stable cycling with high energy and power densities. Such a single-layer chunky particle electrode design can be extended to other advanced battery systems and boost the development of LIBs with fast-charging capability and high energy density.