Mitigating Electrode-Level Heterogeneity Using Phosphorus Nanolayers on Graphite for Fast-Charging Batteries
Min‐Ho Kim, Ju‐Young Kim, Seong‐Hyeon Choi, Tae‐Ung Wi, Ahreum Choi, Jeongwoo Seo, Chek Hai Lim, Chang‐Hyun Park, Hyun‐Wook Lee
Abstract
High Resolution Image Download MS PowerPoint Slide Achieving fast-charging lithium-ion batteries (LIBs) with reliable cyclability remains a significant challenge. In this study, we investigate the use of phosphorus nanolayers as a strategy to enhance the lithiation kinetics and performance of graphite-based composites without inducing lithium (Li) plating on the electrode surface, increasing the delivery capacity. In particular, operando optical microscopy reveals that during fast charging, the concentrated Li-ion flux near the graphite electrode surface impedes Li-ion permeation into the bulk, leading to nonuniform lithiation. In contrast, our designed graphite–P/C composite electrodes exhibit a well-dispersed LiC 6 phase volume fraction throughout the electrodes, indicating the homogeneous lithiation of graphite. Our electrodes maintain consistent cycle retention (94.4%) and high Coulombic efficiency (>99.8%) over 1000 cycles at 1C owing to their enhanced reaction kinetics despite their relatively high capacity. Our findings highlight the potential of using phosphorus-based composites as a promising approach for achieving fast-charging LIBs with enhanced performance and safety.