High Surface Area Graphitic Porous Carbon for Efficient and High‐Energy Li‐Ion and Na‐Ion Capacitors

The graphitic porous carbons derived from coir pith are activated (C‐900) and systematically investigated as a potential electrode material for Li‐ion and Na‐ion capacitors (LICs and NICs), coupled with pre‐lithiated or pre‐sodiated commercial hard carbon (HC) as the battery‐type counter electrode. The C‐900 exhibits outstanding charge‐storage performance in Li/Na half‐cells, which is attributed to its high specific surface area (2086 m 2 g −1 ). The HC is pre‐lithiated (LHC) or pre‐sodiated (NHC) before LIC/NIC assembly, and the mass loading of C‐900 is adjusted based on the performance of HC. The C‐900/HC devices deliver maximum energy densities of ∼153 and ∼128 Wh kg −1 for LIC and NIC, respectively. The temperature‐dependent performance of both LIC and NIC is evaluated, revealing excellent adaptability with capacity retention exceeding 95 and 85%, respectively, across a wide temperature range from –10 to 50 °C. The LIC maintains electrochemical stability over 2,500 cycles, while the NIC remains stable for 1,000 cycles. These results demonstrate that the high‐surface‐area, graphene‐like carbon derived from coir pith serves as a promising positive electrode for next‐generation energy storage devices, offering excellent energy and power performance.