Bioinspired Mineralization under Freezing Conditions: An Approach to Fabricate Porous Carbons with Complicated Architecture and Superior K+ Storage Performance

Bioinspired mineralization is a powerful method for designing and preparing nanomaterials. In this work, we developed a bioinspired mineralization approach under freezing conditions, and fabricated the methyl cellulose (MC)/NaHCO3 flake precursors with a sophisticated hierarchical structure. Based on it, an amazing wing-like porous carbon sheets (WPCSs) assembled by numerous interconnected hollow carbon bubbles was obtained after carbonization and removal of inorganic crystals, which is seldom obtained by other artificial methods. Benefiting from their open framework, large surface area, and enlarged interlayer spacing of graphitized nanocrystallites, the obtained WPCSs exhibited an obvious boost in potassium storage performance. As anode of potassium-ion batteries (PIBs), it showed high reversible capacities of 347 mAh g-1 at 50 mA g-1 and 122 mAh g-1 at 20 A g-1, and relatively stable cyclability for 3000 cycles. The assembled WPCS//WPCS potassium-ion hybrid supercapacitor (PIHC) delivered a high energy...