Bromine‐Modified Graphite for High‐Rate and Stable K‐Storage

ABSTRACT

Graphite (Gr) has been considered as one of the most promising anode materials for potassium‐ion batteries (PIBs) due to its low cost, high electrical conductivity, good chemical stability, and ability to reversibly form intercalation compounds with K ⁺ . However, the large ionic radius of K ⁺ results in sluggish K‐storage kinetics and irreversible disruption of the Gr structure during insertion/extraction, leading to unsatisfactory cycling stability and rate performance. In this work, a bromine‐modified Gr‐based composite (Br‐Gr) was synthesized via a hexabromobenzene (HBB)‐assisted one‐step carbonization method. As a result, the optimized Br‐Gr demonstrates a reversible discharge capacity of 310.1 mA h g ⁻¹ at a current density of 50 mA g ⁻¹ as well as a high‐rate capacity of 109.5 mA h g ⁻¹ at 1000 mA g ⁻¹ , along with excellent cycling stability and high reaction reversibility. This work presents a practical, cost‐effective strategy for preparing high‐performance Gr‐based K‐storage anode materials with promising commercial applications in PIBs.