Researchers at the University of Akron in the United States have developed Mn3O4/C graded porous nanospheres and used them as anode materials for lithium-ion batteries. This type of nanospheres have high reversible specific capacity, excellent stability and extremely long cycle life.

　　Researchers at the University of Akron in the United States have developed Mn3O4/C graded porous nanospheres and used them as anode materials for lithium-ion batteries. The reversible specific capacity of this type of nanospheres is relatively high (when the current is 200?mA/g, the battery capacity is 1237mAh/g), has excellent stability (when the current is 4A/g, the battery capacity is 425mAh/g) and extremely Long cycle life (current is 4A/g, after 3000 cycles of use, there is no obvious capacity degradation).

　　Theoretically, transition metal oxides have high capacity and low cost, making them a promising anode candidate material. Among these materials, Mn3O4 has abundant reserves, is not easy to oxidize, and is electrochemically competitive. As a battery anode material, it has good prospects and is also widely used in the research of various battery materials.

　　However, transition metal oxides can become anode materials for lithium-ion batteries (LIBs), and they have encountered several problems: First, the inherent poor conductivity of metal oxides limits the electron transport of the entire electrode, resulting in low utilization of active materials, Low evaluability. Secondly, the large-volume shrinkage and expansion of metal oxides during the lithiation and delithiation process will cause the electrode to be smashed, thereby accelerating the capacity decay during cycling. As we all know, nano-engineering and carbon hybridization are effective methods to overcome and limit such problems.

　　The research team used a solvothermal reaction to synthesize a self-assembled manganese-based metal composite (Mn-MOC), which has a spherical structure. Then, the researchers transformed the Mn-MOC precursor material into porous Mn3O4/C nanospheres through thermal annealing.

　　Researchers attribute the storage capacity of lithium to the unique porous hierarchical structure of the nanospheres. The nanospheres are composed of Mn3O4 nanocrystals, which are covered with evenly distributed thin carbon shells. The nanostructure has a larger reaction area, enhances conductivity, and is easy to form a stable solid electrolyte interface (SEI) and can adapt to the volume change of the conversion reaction electrode.