Nanostructure and Interface Engineering of Graphite Anodes for High‐Performance Potassium‐Ion Batteries: Mechanisms, Strategies, and Perspectives

Why It Matters

Advancing graphite anodes can unlock low‑cost, high‑energy PIBs, expanding grid‑scale storage options where lithium resources are limited.

Key Takeaways

• K+ diffusion in graphite is sluggish
• Volume expansion damages graphite structure
• SEI instability reduces cycle life
• Interlayer expansion improves K+ intercalation
• Artificial SEI layers boost Coulombic efficiency

Pulse Analysis

Potassium‑ion batteries are gaining traction as a sustainable alternative to lithium technologies, primarily because potassium is abundant and its K⁺/K redox couple sits at a low potential compatible with aluminum current collectors. Graphite, the workhorse anode in lithium‑ion cells, offers structural stability and low cost, yet its performance in PIBs is hampered by sluggish K⁺ diffusion pathways and significant lattice swelling during intercalation. These intrinsic limitations manifest as reduced rate capability and rapid capacity fade, underscoring the need for targeted material engineering.

Recent research converges on two complementary fronts: bulk‑material design and interface manipulation. Expanding the interlayer spacing through chemical intercalants or creating porous morphologies shortens ion travel distances, while heteroatom doping and conductive coatings introduce additional active sites and reinforce structural integrity. Simultaneously, electrolyte formulation and artificial SEI layers mitigate the formation of unstable native SEI, preserving electrode surface chemistry and enhancing Coulombic efficiency. Binder innovations further stabilize electrode cohesion, collectively delivering higher capacities, faster charge rates, and longer cycle life.

When benchmarked against lithium and sodium counterparts, graphite‑based PIB anodes demonstrate competitive energy densities with the added advantage of lower material costs. The review’s forward‑looking perspective emphasizes scalable synthesis routes, in‑situ characterization of interfacial phenomena, and integration with high‑voltage cathodes as critical pathways to commercial viability. As grid‑scale storage demands intensify, these advancements position graphite anodes as a cornerstone for next‑generation, cost‑effective potassium‑ion battery systems.