(603b) Bijel-Derived Materials for Electrochemical Energy Storage and Conversion

Pressing energy demands for national security, distributed power, and portable technologies require the development of next-generation batteries and supercapacitors that can simultaneously deliver high power and energy densities. In order to achieve this goal, the kinetics of ion and electron transport within the electrodes must be enhanced while maintaining a large capacity for energy storage. Therefore, the idealized electrode microstructure in batteries has been envisioned as a three-dimensional, co-continuous arrangement of percolating passages for efficient ion and electron transport that would also enable a large volumetric density of active materials. We report a novel method to produce this distinctive microstructure based on colloidal self-assembly into bicontinuous interfacially jammed emulsion gels (bijels), which are a new class of soft materials with a co-continuous microstructure where two interpenetrating fluid domains are kinetically arrested through jamming of particles at the fluid-fluid interface during spinodal decomposition. Bijels can be converted to electrolytically active composites with co-continuous internal microstructure through simple chemical post processing steps, maintaining the unique morphological characteristics, optimum transport properties, and tunable internal morphology of the original emulsion. In this talk, we will present microstructured composite electrodes that have been synthesized by this technique and demonstrate how their electrochemical characteristics can be tuned over a wide range, allowing for concurrent delivery of high energy and power. The broader applications of this new class of soft materials in electrochemical energy conversion and storage, sensing, and catalysis will also be discussed.