Important progress has been made in the research of new materials for lithium batteries
Recently, the team of Professor Pan Feng from the School of New Materials of Peking University has made important progress in its research work.
As we all know, lithium batteries have been widely used in mobile phones and electric vehicles. The layered material has a high specific capacity and is used as a positive electrode material for power batteries in high-end electric vehicles (such as Tesla electric vehicles) at home and abroad. The requirements for performance and rate performance are also getting higher and higher. There are many ways to improve the electrochemical performance of transition metal oxide layered cathode materials. Among them, the cycle performance and rate performance of the material can be improved by doping other elements, such as (Al, Ti), to meet the current demand for power batteries. The demand for charging and lifespan has therefore become a hot spot in current research. The mechanism of how to effectively dope and improve performance after doping is not yet understood, and further research is needed.
Peking University School of New Materials has made progress in improving the performance of lithium battery material interface gradient reconstruction
Recently, the clean energy center research team led by Professor Pan Feng, School of New Materials, Peking University Shenzhen Graduate School, used neutron diffraction, x-ray absorption spectroscopy (XPS), high-precision and atomic scale microscopes (HR-TEM and spherical aberration TEM) Combined with first-principles quantum chemistry calculations, a new type of interface reconstruction formed by Ti gradient doping at the interface of transition metal oxide layered materials of lithium batteries, improved battery charge and discharge rate and cycle stability, and related mechanisms have been systematically studied. The work was recently published in Advanced Energy Materials (IF=24.884), a well-known journal in the field of energy materials.
Pan Feng’s research group used the independently innovative Ti gradient doping method to construct about 6 nanometers thick Ti-O structure element and Li/Ni reaction on the surface of the high nickel cathode layered material LiNi0.8Co0.2O2 (NC82). New interface structure. Because of the strong chemical bond of Ti-O, the oxygen atom stability of the interface during the synthesis process is improved. The reconstructed interface can prevent the material from reacting with H2O, CO2 and electrolyte, and inhibit the formation of surface during the synthesis process. Miscellaneous phases (such as NiO type rock salt phase, Li2CO3, etc.) to improve the electrochemical performance of the material, especially the rate performance and cycle performance. This structured surface layered phase protection mechanism can overcome the damage of conventional surface inert coating methods to charge transport. It is based on the adjustment of the surface chemical properties of the high nickel material itself to obtain a positive electrode with high capacity, high rate, and high stability. Materials provide new means.
