Recent Progress on Non‑Biomass Carbon‑Based Anodes for Sodium‑Ion Batteries

This review identify itself by concerning exclusively on synthetic non‑biomass carbon anodes. Providing a holistic investigation that connected fundamental sodium (Na) storage mechanisms to scalable synthesis strategies for performance optimization. The most promising anode material in Na-ion batteries (SIBs) is hard carbon (HC), which is cost-effective. Its wide-scale application is however, limited due to difficulty in the comprehension and optimization. Particularly, initial coulombic efficiency (ICE) and long run durability. This review developing a comprehensive model that connects the atomic structure and surface chemistry to the electrochemical behavior of HC anodes. The discussion starts with the reconsideration of the basic imperfection of Na⁺ storage by adsorption, interlayer intercalation, nanopore filling assisted. Then, further study considers the development of carbons derived as non-biomass. These are graphene-based composites and carbon nanotubes (CNTs), the dynamics of capacity and reversibility being controlled by doping, pore engineering, and surface functionalization. Specific focus is put on defect management, solid-electrolyte interphase (SEI) stabilization and structural hierarchy role in plateau contribution and ICE improvement. New synthesis methods are discussed as scalable ways of assembling high-performance, mechanically stable carbon structures. Lastly, the review summarizes the future research direction bridging material design with full cell performance requirements.