A magnetic/force coupling assisted lithium-oxygen battery based on magnetostriction and piezoelectric catalysis of CoFe2O4/BiFeO3 cathode

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. Magnetic/Force Coupling assisted Li−O 2 battery relies on magnetostriction and piezoelectric catalysis principle to generated electrons and holes promote oxygen reduction and evolution to improve battery performance, at the same time, the magnetohydrodynamic effects inhibited the growth of lithium anode dendrites It provides a new strategy for developing Li−O 2 battery in energy storage. • A magnetic/force coupling assisted Li−O 2 battery was established for the first time. • It is favorable to reducing the overpotential during charge and discharge processes of the Li-O 2 battery. • It is discovered that the magnetic field is more conducive to the uniform deposition behavior of lithium anode.