Tuning Li ⁺ and Na ⁺ Functionality in Renewable Carbon Electroactive Material Through Site‐Specific Nanostructural Disorder

Understanding the hybrid structural characteristics of carbon remains a significant challenge, hindering the development of clear design principles for optimizing electrode materials in energy storage systems-particularly in lithium-ion (Li-ion) and sodium-ion (Na-ion) batteries. Traditionally, the localized structural disorder and intrinsic porosity of carbon have been regarded as the primary contributors to its high storage capacity in Na-ion batteries. However, our investigation reveals that the hybrid structural features of carbon play a more dominant role in enhancing energy storage performance in Li-ion systems compared to Na-ion counterparts. Through comprehensive materials characterization and electrochemical analysis, we establish a direct correlation between the local microstructural attributes of carbon and its ion storage kinetics which elucidate the distinct ion-storage mechanisms that differentiate Li-ion from Na-ion systems. This study reinforces our findings that configurational defects are crucial for achieving high initial storage capacity in carbon crafted with mixed-phase structures, but the in-plane size of nano-layered microdomains plays a key role in ensuring long-term stable storage capacity in rechargeable batteries.