Green transformation of photovoltaic silicon mud to a high-performance P-Si@RGO anode material by magnesium thermal reduction via electrostatic assembly technology

In this paper, with the goal of developing a high-performance silicon-based negative electrode through a reasonable green design using simple magnesium thermal reduction and pickling combined methods. Specifically, we utilize inexpensive photovoltaic waste silicon mud as the silicon source to synthesize porous silicon. Subsequently, we utilized self-produced porous silicon as the raw material and graphene as the coating material to fabricate a graphene-coated porous silicon-based negative electrode material with excellent cycling stability. We employ the PW91 method, which is based on density functional theory (DFT) using the generalized gradient approximation (GGA), to compute the first principles of both silicon-based materials and graphene-coated silicon/graphene composites. The study revealed that the P-Si@RGO composite exhibited excellent electrochemical properties. When adding 150 mL of graphene oxide with a concentration of 0.2 mg/mL. Even after the 100th cycle at a current density of 100 mA·g −1 , the specific discharge capacity of the P-Si@RGO electrode remains high at 1167.6 mAh·g −1 . At the same time, the results of DFT calculations also show that graphene can improve the conductivity of silicon materials. In summary, the experimental results are consistent with the results of the first-principal calculation, indicating that the computer simulation can predict the accuracy of the experiment, verify the empirical conclusions, and indicate the direction for designing the experimental scheme.