Semi-solid lithium/oxygen flow battery: an emerging, high-energy technology

Lithium-Air (O 2 ) batteries are considered one of the next-generation battery technologies, due to their very high specific energy. In parallel, Redox Flow Batteries (RFBs) are getting much attention for energy transition because of their highly flexible design that enables the decoupling of energy and power. However, commercial RFBs still suffer from low energy density. One of the solutions proposed to increase the energy density is the combination of the high energy density of the Li/O 2 battery with the flexible and scalable architecture of redox flow batteries in semi-solid flow Li/O 2 batteries. The challenging activities to develop materials and components, and to prototype semi-solid flow Li/O 2 batteries are here presented and discussed. • Lithium-air batteries (LABs) are emerging for their high theoretical energy density. • Semi-solid redox flow batteries boost capacity and energy of redox flow batteries (RFB). • Semi-Solid Li/O 2 Flow Batteries combine the advantages of LABs and tRFBs.