Designing silicon-carbon composite anode architectures with controlled porosity for pearl river delta electric vehicle battery manufacturing

How can lithium-ion battery manufacturers in the Pearl River Delta region meet the rising energy density demands of next-generation electric vehicles? Silicon-based anodes hold the answer, yet their massive volume swings during charge-discharge cycles remain a barrier. This research reports a spray-drying and carbonization route for preparing silicon-carbon (Si/C) composite anodes with tuneable internal porosity. Silicon nanoparticles (average diameter 78.4 nm) were blended with a pitch-derived carbon precursor at mass ratios of 1:9 through 4:6 and converted into spherical secondary particles at 900 °C under nitrogen. Porosity was adjusted by varying the sacrificial template content from 5 to 25 wt%. Nitrogen adsorption analysis showed specific surface areas between 23.1 and 47.3 m²/g, with a dominant mesopore population centred near 8.6 nm. The optimised composite (Si = 3:7, 15 wt% template) delivered a first-cycle discharge capacity of 1,847 mAh/g at 0.1 C and retained 1,089 mAh/g after 500 cycles, corresponding to 58.9% capacity retention. Electrochemical impedance spectroscopy confirmed that charge-transfer resistance dropped from 134.7 to 61.2 Ω as porosity rose. Coulombic efficiency stabilised above 99.3% from cycle 10 onward. These findings suggest that controlled-porosity Si/C architectures offer a practical path toward high-capacity anode production compatible with existing Pearl River Delta battery manufacturing lines.