Ultrahigh‐Rate Na/Cl2 Batteries Through Improved Electron and Ion Transport by Heteroatom‐Doped Bicontinuous‐Structured Carbon

Rechargeable sodium/chlorine (Na/Cl2) batteries are emerging candidates for sustainable energy storage owing to their superior energy densities and the high abundance of Na and Cl elements. However, their practical applications have been plagued by the poor rate performance (e.g., a maximum discharge current density of 150 mA g−1), as the widely used carbon nanosphere cathodes show both sluggish electron‐ion transport and reaction kinetics. Here, by mimicking the sufficient mass and energy transport in a sponge, we report a bicontinuous‐structured carbon cubosome with heteroatomic doping, which allows efficient Na+ and electron transport and promotes Cl2 adsorption and conversion, thus unlocking ultrahigh‐rate Na/Cl2 batteries, e.g., a maximum discharge current density of 16,000 mA g−1 that is more than two orders of magnitude higher than previous reports. The optimized solid–liquid–gas (carbon–electrolyte–Cl2) triple interfaces further contribute to a maximum reversible capacity and cycle life of 2,000 mAh g−1 and 250 cycles, respectively. This study establishes a universal approach for improving the sluggish kinetics of conversion‐type battery reactions, and provides a new paradigm to resolve the long‐standing dilemma between high energy and power densities in energy storage devices. A rechargeable Na/Cl2 battery with an ultrahigh rate capability (16,000 mA g−1) has been realized using a bicontinuous‐structured carbon cubosome with heteroatomic doping, which enables efficient Na+ and electron transport and promoted Cl2 adsorption and conversion. It provides a new paradigm to solve the dilemma between energy density and power density in energy storage devices.