The research, led by Professor Loh Kian Ping from the Department of Chemistry at NUS, could pave the way for the development of ultra-stable, high capacity and environmental friendly rechargeable batteries.
Rechargeable batteries are the key energy storage component in large-scale battery systems from electric vehicles to smart renewable energy grids and, in order to meet this growing demand, researchers are looking to develop more sustainable, environmentally friendly methods of producing them – one method being to use organic materials as an electrode in the rechargeable battery.
Organic electrodes leave a lower environment footprint during production and disposal making them a more eco-friendly alternative to inorganic metal oxide electrodes commonly used in rechargeable batteries. The structures of organic electrodes can also be engineered to support high energy storage capabilities. The main challenge in their use, however, is the poor electrical conductivity and stability of organic compounds when used in batteries. The organic materials currently used - such as conductive polymers and organosulfer compounds - also face rapid loss in energy after multiple charges.
To overcome this, Prof Loh and his research team synthesised a novel organic compound 3Q (π-conjugated quinoxaline-based heteroaromatic molecule) that has up to six charge storage sites per molecule in an effort to enhance its conductivity and energy retention.
When hybridised with graphene and used in an ether-based electrolyte, the team observed that the 3Q-based electrode displayed a high electrical conductivity of 395 milliampere hour per gram. It also exhibited a strong energy retention capability after multiple cycles of charge and discharge.
Prof Loh explained, “Our study provides evidence that 3Q, and organic molecules of similar structures, in combination with graphene, are promising candidates for the development of eco-friendly, high capacity rechargeable batteries with long life cycles.”