(294e) Gyroidal 3-D Electrochemical Energy Storage Nanoarchitecture

Authors: 
Werner, J. G., Cornell University
Rodríguez-Calero, G., Cornell University
Abruña, H. D., Cornell University
Wiesner, U., Cornell University
Gyroidal mesoporous carbon monoliths are employed to integrate all electrochemical energy storage device components, namely anode, electrolyte, and cathode, into a single three-dimensionally (3‑D) interdigitated nanoarchitecture. Integrating electrodes and electrolyte into a 3-D interdigitated network structure allows for small ion diffusion distances, while allowing phase connectivity and preventing wasteful porosity. Hence, such 3-D electrical energy storage devices have the potential for structure-driven power enhancements, but have remained challenging to achieve on the nanoscale. The lack of methods for fabricating and assembling the appropriate functional materials in 3-D co-continuous nanoarchitectures is a key issue holding back the development of such intricate 3‑D device architectures. The components in electrochemical energy storage systems have stringent requirements on their functionality; the electrodes need to display electrical conductivity in combination with redox-activity with an electrochemical potential difference between anode and cathode, and the electrolyte needs to be ionically conductive but electronically insulating. In 3-D interdigitated designs, the individual components cannot be fabricated separately and subsequently assembled or layered, but synthesis and assembly are inherently connected. In particular, the nanoconfined synthesis of functional materials in the presence and close proximity of the other functional device components necessitates synthetic procedures that are compatible between all materials. Here we present pathways to such electrochemical energy storage systems with all functional phases integrated in a triblock terpolymer derived core-shell double gyroid morphology. We devised a step-wise bottom-up strategy to synthesize and incorporate all functional materials within each other in a compatible way. Our 3-D interdigitated design comprises a gyroidal carbon anode network that is electrochemically coated with an ultrathin polymer electrolyte in a self-limiting and -regulating method. The 3-D continuously nanoporous anode-electrolyte monolith is in turn filled with a sulfur-polymer hybrid cathode that is polymerized in the confinement of the nanoporous network and exhibits lithium redox-activity and electrical conductivity. All phases are less than 20 nm in their layer dimensions and integrated throughout a macroscopic monolith. Despite the small separation distances, the solid-state nano-3-D energy storage system exhibits battery-like characteristics and can be cycled numerous times.