I-Corps: Hybrid Protein Graphene Electrodes for Supercapacitors

University Of California-Davis, Davis CA

Investigators

Abstract

Our modern technical society needs devices able to store and deliver energy effectively, for applications including i) mobile electronic devices (ii) electric transport via cars, electric bikes, "hoverboards" and other vehicles (iii) implanted biomedical sensor devices, and (iv) electrical energy storage for alternative power sources such as windmills and photovoltaics, because "the wind doesn?t always blow, and the sun doesn?t always shine." Current commercial storage is dominated by batteries, especially lithium ion batteries ubiquitous in cell phones, laptops, Tesla electric vehicles, etc, because they have the highest energy density by weight. However, batteries can heat up (not desirable for medical implants), contain toxic components (as in the lead acid batteries common in electric bikes), and have safety issues (witness the string of fires in "hoverboards" recently). It is worth examining other options like supercapacitors, which store energy by nonchemical, nontoxic means, can deliver electrical energy far more rapidly than batteries, and which do not heat or represent fire danger. While supercapacitors have long occupied niche markets as secondary power sources or for rapid charging applications, they do not store as much energy per unit mass as lithium ion batteries, and conventional designs are more expensive, based dominantly on the cost and materials in the supercapacitor charging terminals (electrodes). This I-Corps team proposes a new approach that combines the revolutionary material graphene with designed proteins to provide supercapacitor electrodes that are cheaper and have high energy density and so could be disruptive for the energy storage market. In the short term, this I-Corps team hopes to produce low cost, environmentally benign small supercapacitors which can potentially be used in medical devices (since they do not heat up and are benign), niche transportation applications (such as replacement for batteries in e-bikes and cars), and potentially novel devices such as nontoxic, non-flame based biodegradable replacements for flares. In the long term, they could help supply reliable and quickly discharged electrical grid storage to go hand-in-hand with intermittent energy generation from renewables so that the transfer of electricity remains stable and disruption free. During the I-Corps program, the team intends to interview stakeholders in general energy storage technologies, grid storage (from the storage provider side and the energy storage side), home energy storage, energy storage in medical devices, and energy storage in various transportation contexts, especially e-bikes and cars. The team does not plan to go after energy storage in the consumer electronics market, where the technology is sufficiently mature.