Graphene-based quasi-solid-state lithium–oxygen batteries with high energy efficiency and a long cycling lifetime

An aprotic lithium–oxygen battery with an ultrahigh theoretical energy density has attracted significant attention as the next-generation electrochemical energy device demanded by all-electric vehicles and other high-energy devices. Extensive effort has recently been devoted to improving the performances of cathodes, anodes, and electrolytes. However, as an integrated system, the overall battery properties are not determined by the individual components but by the synergy of all components. Despite important progress in the development of cathodes, anodes, and electrolytes, the system-level design and assembly of lithium–oxygen batteries have not benefited from these recent advances. Here, we report a graphene-based quasi-solid-state lithium–oxygen battery consisting of a rationally designed 3D porous graphene cathode, redox mediator-modified gel polymer electrolyte, and porous graphene/Li anode. This integrated prototype battery simultaneously addresses the major challenges of lithium–oxygen batteries and achieves stable cycling at a large capacity, low charge overpotential and high rate in both coin-type and large-scale pouch-type batteries. For the first time, these lithium–oxygen batteries as a whole device deliver gravimetric and volumetric energy densities higher than those of a commercial Li-ion polymer battery. This study represents important progress toward the practical implementation of full-performance lithium–oxygen batteries. An experimental lithium battery ideal for powering electric vehicles is one step closer to commercialization thanks to graphene technology. While lithium–oxygen batteries offer extremely high energy storage in a low-weight package, they often fail prematurely due to irreversible formation of precipitates during recharging. To overcome these issues, Mingwei Chen from Tohoku University in Sendai, Japan, and co-workers have constructed battery cathodes and anodes from a new porous form of graphene. The team’s approach sandwiches a conductive gel between a bare 3D nanoporous graphene film and one loaded with lithium ions. The abundant active sites for oxygen reduction in the device, coupled with a gel design that facilitates ion transport, inhibited precipitation reactions for up to 100 charge cycles. A prototype ‘pouch’-type battery produced more energy per square centimeter than conventional lithium-ion cells. A graphene based quasi-solid state rechargeable Li-O2 battery is developed by utilizing 3D nanoporous graphene cathode, TTF modified quasi-solid state GPE and porous graphene/Li anode. This integrated prototype battery simultaneously addresses the major challenges of Li-O2 batteries in energy efficiency, lifetime and safety and present an important progress in practical implementation of full performance Li-O2 battery.