New Japanese research increases battery capacity by more than twice

　　The composite material is used as the negative electrode material of lithium and sodium ion rechargeable batteries, which can increase the charge and discharge capacity of the battery by more than twice, and can prolong the repeated service life, solving the problem of incapability of both capacity and service life.

　　According to foreign media reports, the new negative electrode material announced by Japan can increase the battery capacity by more than twice.

　　The Japan Institute for Material and Materials Research (NIMS) recently announced that one of their research teams has successfully synthesized manganese oxide nanosheets and graphene alternately overlapping materials. The composite material is used as the negative electrode material of lithium and sodium ion rechargeable batteries, which can increase the charge and discharge capacity of the battery by more than twice, and can prolong the repeated service life, solving the problem of incapability of both capacity and service life.

　　High capacity is one of the goals of secondary batteries. At present, carbon materials are used in their negative electrodes. Theoretically, transition metal oxides have high capacity and are expected to become alternatives to carbon materials. In particular, manganese oxide with a layered structure is exfoliated into single-molecule-thick nanosheets, and used as a negative electrode. The surface is all active, which can greatly increase the capacity. However, the difficulty of manganese oxide is that the structure is easily destroyed by repeated charging and discharging, and the nanosheets are also prone to agglomerate into clusters.

　　The research team dispersed manganese oxide nanosheets in the solution and mixed them with graphene to synthesize an alternating multilayer laminated composite material. Both manganese oxide and graphene are negatively charged and usually repel each other. As early as 2015, the research team solved the repulsion problem by chemically modifying graphene to make it positively charged, and achieved the highest capacity and longest life of the metal oxide anode materials at that time.

　　This time, by combining the two substances at the molecular level, we have obtained high characteristics that are difficult to achieve with a single material. In addition to being used in rechargeable batteries, composite materials can also greatly improve the performance of energy storage and conversion systems such as supercapacitors and electrode catalysts.