Biomimetic mineralization coupling with seeds-induced foaming for optimizing carbon microstructure towards ultrafast sodium ion storage

Abstract

Porous carbons show high surface area and capacity but suffer from uncontrollable structure, inferior initial Coulombic efficiency (ICE) and rate capability in Na+ storage. Herein, we propose a strategy of biomimetic mineralization coupling with seeds-induced foaming to optimize porous carbon sheets (CNMK) with excellent performance in ICE of 90 %, rate capability of 528 mAh g−1 at 0.05 A g−1 and 139 mAh g−1 at 50 A g−1, and capacity retention of 81 % over 5500 cycles at 20 A g−1 (half-cell); energy density of 223 Wh kg−1 (CNMK//Na3V2(PO4)3 full-cell). The reasons for such outstanding performance are as follows: (1) The “disorder-in-order” structure (rich defects/pores in graphitic network) favours Na+ storage and electrons transportation (same electrolyte). (2) The ether electrolyte shows superior Na+ storage kinetics than ester electrolyte (same anode). These results will provide an effective and practical strategy for developing advanced carbon materials and give new insights into the synergistic effect between carbon structure and ether electrolyte in Na+ storage.