Regulating Oxygen Configuration in Hierarchically Porous Carbon Nanosheets for High‐Rate and Durable Na+ Storage

Abstract Surface oxygen functionalities (particularly C−O configuration) in carbon materials have negative influence on their electrical conductivity and Na + storage performance. Herein, we propose a concept from surface chemistry to regulate the oxygen configuration in hierarchically porous carbon nanosheets (HPCNS). It is demonstrated that the C−O/C=O ratio in HPCNS reduces from 1.49 to 0.43 and its graphitization degree increases by increasing the carbonization temperature under a reduction atmosphere. Remarkably, such high graphitization degree and low C−O content of the HPCNS‐800 are favorable for promoting its electron/ion transfer kinetics, thus endowing it with high‐rate (323.6 mAh g −1 at 0.05 A g −1 and 138.5 mAh g −1 at 20.0 A g −1 ) and durable (96 % capacity retention over 5700 cycles at 10.0 A g −1 ) Na + storage performance. This work permits the optimization of heteroatom configurations in carbon for superior Na + storage.