Diatomite and Glucose Bioresources Jointly Synthesizing Anode/Cathode Materials for Lithium-Ion Batteries

Large-scale popularization and application make the role of lithium-ion batteries increasingly prominent and the requirements for energy density have increased significantly. The silicon-based material has ultra-high specific capacity, which is expected in the construction of next-generation high specific-energy batteries. In order to improve conductivity and maintain structural stability of the silicon anode in application, and further improve the energy density of the lithium-ion battery, we designed and synthesized carbon-coated porous silicon structures using diatomite and polysaccharides as raw materials. The electrode materials constructed of diatomite exhibit porous structures, which can provide fast transport channels for lithium ions, and effectively release the stress caused by volume expansion during cycling. At the same time, the electrical conductivity of the materials has been significantly improved by compounding with biomass carbon, so the batteries exhibit stable electrochemical performance. We systematically studied the effect of different contents of biomass carbon on the Li₂MnSiO₄/C cathode, and the results showed that the carbon content of 20% exhibited the best electrochemical performance. At a current density of 0.05C, the capacity close to 150 mAh g⁻¹ can be obtained after 50 cycles, which is more than three times that of without biomass carbon. The silicon-based anode composited with biomass carbon also showed excellent cycle stability; it could still have a specific capacity of 1063 mAh g⁻¹ after 100 cycles at the current density of 0.1 A g⁻¹. This study sheds light on a way of synthesizing high specific-capacity electrode materials of the lithium-ion battery from natural raw materials.