A layered/spinel heterostructured cathode for Li-ion batteries prepared by ultrafast Joule heating

Spinel LiMn2O4 is one of the most promising cathode materials due to its low cost, high discharge voltage (-4.0 V), and non-toxicity. However, it suffers from insufficient cycling performance caused by irreversible phase transition and Mn dissolution. In addition, the low synthesis efficiency caused by the long heating time also plagues its application and depletes the cost merits of raw materials. Herein, we report a heterostructured cathode material of electrochemically-inert layered Li2MnO3 and active spinel LiMn2O4 phases, which is synthesized in seconds by ultrafast Joule heating. The heterostructure is rapidly formed as a result of the nonequilibrium process produced by the ultrafast Joule heating rate. The inert layered phase serves as a structure stabilization agent to suppress the structure damage and Mn dissolution, thus promising an excellent electrochemical performance with a high capacity retention of 83 % after 800 cycles at 5C. Our findings provide an efficient design and synthesis strategy for developing high-performance and low-cost cathode materials.