This paper demonstrates that nanospace engineering of KOH activated carbon is possible by controlling the degree of carbon consumption and metallic potassium intercalation into the carbon lattice during the activation process. High specific surface areas, porosities, sub-nanometer (<1 nm) and supra-nanometer (1-5 nm) pore volumes are quantitatively controlled by a combination of KOH concentration and activation temperature. The process typically leads to a bimodal pore size distribution, with a large, approximately constant number of sub-nanometer pores and a variable number of supra-nanometer pores. We show how to control the number of supra-nanometer pores in a manner not achieved previously by chemical activation. The chemical mechanism underlying this control is studied by following the evolution of elemental composition, specific surface area, porosity, and pore size distribution during KOH activation and preceding H(3)PO(4) activation. The oxygen, nitrogen, and hydrogen contents decrease during successive activation steps, creating a nanoporous carbon network with a porosity and surface area controllable for various applications, including gas storage. The formation of tunable sub-nanometer and supra-nanometer pores is validated by sub-critical nitrogen adsorption. Surface functional groups of KOH activated carbon are studied by microscopic infrared spectroscopy.
Zn powder (Zn‐P)‐based anodes are considered ideal candidates for Zn‐based batteries because they enable a positive synergistic integration of safety and energy density. However, Zn‐P‐based anodes still experience easy corrosion, uncontrolled dendrite growth, and poor mechanical strength, which restrict their further application. Herein, a mixed ionic‐electronic conducting scaffold is introduced into Zn‐P to successfully fabricate anti‐corrosive, flexible, and dendrite‐free Zn anodes using a scalable tape‐casting strategy. The as‐established scaffold is characterized by robust flexibility, facile scale‐up synthesis methodology, and exceptional anti‐corrosive characteristics, and it can effectively homogenize the Zn2+ flux during Zn plating/stripping, thus allowing stable Zn cycling. Benefiting from these comprehensive attributes, the as‐prepared Zn‐P‐based anode provides superior electrochemical performance, including long‐life cycling stability and high rate capability in practical coin and flexible pouch cells; thus, it holds great potential for developing advanced Zn‐ion batteries. The findings of this study provide insights for a promising scalable pathway to fabricate highly efficient and reliable Zn‐based anodes and will aid in the realization of advanced flexible energy‐storage devices.
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