School of Materials Science and Engineering , Ocean University of China , Qingdao 266100 , People's Republic of China.
College of Science , China University of Petroleum (East China) , Qingdao 266580 , People's Republic of China.
ACS Nano. 2019 Oct 22;13(10):11582-11592. doi: 10.1021/acsnano.9b05284. Epub 2019 Oct 1.
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 methyl cellulose (MC)/NaHCO flake precursors with a sophisticated hierarchical structure. Based on this, amazing wing-like porous carbon sheets (WPCSs) assembled by numerous interconnected hollow carbon bubbles were obtained after carbonization and removal of inorganic crystals, which are 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 an anode of potassium-ion batteries, they showed high reversible capacities of 347 mAh g at 50 mA g and 122 mAh g at 20 A g and relatively stable cyclability for 3000 cycles. The assembled WPCS//WPCS potassium-ion hybrid supercapacitor delivered a high energy density of 108 Wh kg at a power density of 280 W kg. Given the cost effectiveness and green process, the modified bioinspired mineralization under freezing conditions would provide a facile and green way for exploring porous carbons with controlled structures and rich multifunction.
仿生矿化是设计和制备纳米材料的一种强有力的方法。在这项工作中，我们在冷冻条件下开发了一种仿生矿化方法，制备了具有复杂分级结构的甲基纤维素 (MC)/NaHCO3 薄片前体。在此基础上，经过碳化和去除无机晶体，得到了由无数相互连接的空心碳泡组装而成的翼状多孔碳片 (WPCS)，这是其他人工方法很少获得的。得益于其开放的骨架、大的表面积和石墨化纳米晶层间间距的增大，所得到的 WPCS 在钾存储性能方面表现出明显的提升。作为钾离子电池的阳极，它们在 50 mA g 时表现出 347 mAh g 的高可逆容量，在 20 A g 时表现出 122 mAh g 的高可逆容量，并且在 3000 次循环后具有相对稳定的循环性能。组装的 WPCS//WPCS 钾离子混合超级电容器在 280 W kg 的功率密度下提供了 108 Wh kg 的高能量密度。鉴于其成本效益和绿色工艺，冷冻条件下改性的仿生矿化将为探索具有可控结构和丰富多功能的多孔碳提供一种简便、绿色的方法。
