Chinese Academy of Sciences Institute of Physics Li Yuming doctoral researcher, Hu Yongsheng researcher and so on by hydrothermal method to obtain a hard carbon microspheres, and then use cotton as a precursor through a one-step carbonization method to obtain a hard carbon microtubules, although hard carbon has excellent Of the storage capacity, but its high cost limits the industrial application. Then they proposed to add a second phase, such as a hard carbon precursor, to the soft carbon precursor asphalt, using an interaction between the two to obtain an amorphous carbon material with a high degree of disorder, and this composite precursor has The higher carbon production rate (about 60%), as a negative electrode material for sodium ion batteries, exhibits a specific capacity of up to 250 mAh / g, excellent cycle stability and magnification performance.
China has successfully developed low-cost sodium ion batteries
Recently, they made a breakthrough on the carbon-based anode materials of sodium ion batteries. Using a relatively low cost anthracite as a precursor, a carbon anode material with excellent storage capacity was obtained by simple pulverization and one-step carbonization. Pyrolysis of anthracite is a soft carbon material, but unlike the soft carbon material from the asphalt, it still has a high degree of disorder at 1600 ° C, with a carbon production rate of up to 90% and a storage capacity of 220 mAh / G, excellent cycle stability. The most important is in all the carbon-based anode material has the highest price. The application prospect is also validated in the flexible battery, and the energy density of the flexible battery made by using it as the negative electrode and the Cu-based oxide as the positive electrode reaches 100 Wh / kg, and the capacity retention rate is 80% at 1C charge / discharge ratio %, - 20 ℃ discharge capacity of 86% room temperature, cycle stability, and through a series of safety tests for lithium-ion batteries. Low-cost sodium ion battery development success is expected to be the first to be used in low-speed electric vehicles, low-speed electric vehicles lead-free, with the technology further mature, will be extended to the communications base stations, household energy storage, power storage and other fields.