(196c) All-Solid-State Li?Air Battery Based on Hollow Carbon Spheres Catalysts Derived from a Sol–Gel Route

Regarding energy and environmental crisis, high-performance energy storage technologies (or devices) for diverse applications have attracted more attention than ever. Lithium-air batteries reveal a rapid development throughout the world due to their higher theoretical specific energy density (5200 Wh kg^−1) than traditional batteries. However, as should be noted that, several challenges have been identified, including safety, reliability and electrochemical performance. Especially, the safety issue caused by the use of flammable and volatile organic liquid electrolyte, which is likely to leak and decompose at high temperatures, has become a major focus recently. Herein, a new type of all-solid-state Li-air battery comprised of Li_1+xAl_yGe_2-y(PO₄)₃ (LAGP) inorganic solid electrolyte, lithium metal anode and hollow carbon spheres catalysts cathode has been fabricated. In the LAGP solid electrolyte, Al³⁺ replacing Ge⁴⁺ can introduce extra lithium in the structure and improve total lithium ion conductivity. A general sol–gel route has been proposed to form a coating of resorcinol–formaldehyde (RF) resin with cationic surfactant assisted on the polystyrene (PS) spheres nanostructure. The hollow-sphere carbons can be successfully derived through high temperature carbonization under an inert atmosphere to remove the PS spheres template. Its porous morphology features is benefit for the fast ion/electron transfer, thus mitigating structural degradation and pore blockage during cycling process. The battery electrochemical performance as well as the reaction mechanism of the cells in an air atmosphere has been studied. This all-solid-state Li-air battery can succeed in discharging and charging. Our work shows that the use of a stable solid electrolyte may be beneficial to solve the inherent safety problems of Li-air batteries.