Effect of Hot Pressing on the Electrochemical Performance of Multilayer Holey Graphene Materials in Li-ion Batteries

Annealing and pressing are useful for improvement of the structural ordering of graphitic materials. Depending on the processing conditions, this may cause a gain or deteriorate the performances of graphitic anodes in batteries. In the present work, we study the effect of hot pressing on the interaction of multilayer holey graphene (HG) material with lithium ions. The initial HG sample with the holes of about 0.6–2 nm was pressured at 100 bar and room temperature, 600 °C, and 800 °C or at 500 bar and 800 °C. The analysis of the samples using X-ray diffraction detected an increase in the thickness of graphene stacks after pressing. Electrochemical tests revealed the best performance for the HG sample produced at 100 bar and 600 °C. A rise of the temperature and pressure reduces the contribution from cross-plane diffusion of lithium ions in the HG capacity.