Nickel‐promoted Electrocatalytic Graphitization of Biochars for Energy Storage: Mechanistic Understanding using Multi‐scale Approaches

Abstract

AbstractOwing to high‐efficiency and scalable advantages of electrolysis in molten salts, electrochemical conversion of carbonaceous resources into graphitic products is a sustainable route for achieving high value‐added carbon. To understand the complicated kinetics of converting amorphous carbon (e.g. carbonized lignin‐biochar) into highly graphitic carbon, herein this study reports the key processing parameters (addition of Ni, temperature and time) and multi‐scale approach of nickel‐boosted electrochemical graphitization‐catalysis processes in molten calcium chloride. Upon both experiments and modellings, multi‐scale analysis that ranges from nanoscale atomic reaction to macroscale cell reveal the multi‐field evolution in the electrolysis cell, mechanism of electrochemical reaction kinetics as well as pathway of nickel‐boosted graphitization and tubulization. The results of as‐achieved controllable processing regions and multi‐scale approaches provide a rational strategy of manipulating electrochemical graphitization processes and utilizing the converted biomass resources for high value‐added use.