Architected Carbon Structures for Energy Storage

Carbon materials, owing to their excellent electrical conductivity, tailor-ability, inexpensiveness, and versatility, have been extensively studied as electrode materials for energy storage devices, including batteries and supercapacitors. In this talk, I will discuss how to combine conventional materials/chemical synthesis with 3D printing techniques to develop architected carbon electrode materials for supercapacitors. The capacitance of carbon-based supercapacitor electrodes has remained at a mediocre level between 100 and 200 F/g for decades. Until recently, a new family of carbon materials termed hierarchical porous carbons has pushed the capacitance to new benchmark values beyond 300 F/g and has revitalized the exploration of carbon materials for supercapacitors. We have recently developed some hierarchical porous carbon areogels contain different scales of pores inter-connected together and assembled in hierarchical patterns, through a combination of freeze drying, template, chemical etching and 3D printing. These porous carbons have an open porous structure, providing an extremely large and accessible surface area. They can be used as electric double layer materials that enable ultrafast charging/discharging and retain outstanding capacitive performance even at ultralow temperatures (-70 °C). They can serve as 3D conductive scaffolds/current collectors to support pseudo-capacitive materials with ultrahigh mass loadings. These findings exemplified how to use a deterministic structure to improve the rate capability of supercapacitors and their capacitances at ultrahigh current densities and mass loadings and ultralow temperatures, which are long-standing challenges for SCs.