A magnetic/force coupling assisted lithium-oxygen battery based on magnetostriction and piezoelectric catalysis of CoFe2O4/BiFeO3 cathode
Song‐Lin Tian, Lina Song, Li-Min Chang, Wanqiang Liu, Huan‐Feng Wang, Ji‐Jing Xu
Abstract
The high energy density of Li−O 2 batteries surpasses all existing batteries , and it holds the potential to emerge as the most outstanding solution for energy storage in the future. However, the insulated, insoluble discharge product (Li 2 O 2 ) has impeded the practical applications. Conventional catalyst design based on electronic structure and interfacial charge transfer descriptors are incapable of overcoming these limitations of Li 2 O 2 . Herein, a magnetic/force coupling assisted Li−O 2 battery based on magnetostrictive and piezoelectric catalysis with CoFe 2 O 4 /BiFeO 3 core-shell structure cathode was established for the first time. An external magnetic field is introduced to produce a magnetostrictive stress on CoFe 2 O 4 , contributing to the piezoelectric electron hole transport by the generated piezoelectric potential energy with a built-in electric field based on the piezoelectric catalytic mechanism, and thus promoting the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) kinetics, and reducing the overpotential during charge/discharge. The magnetic/force coupling assisted Li−O 2 battery equipped with the unique CoFe 2 O 4 /BiFeO 3 cathode deliver an ultra-low charging platform of 3.49 V and an ultra-high discharge platform of 2.83 V. This unique magnetic/force assisted strategy provides an important insight into solving the high overpotential in metal-air battery systems.