Stabilizing dimensional changes in Si-based composite electrodes by controlling the electrode porosity: An in situ electrochemical dilatometric study

► A porosity-controllable Si-based composite electrode was fabricated. ► PMMA showing unzipping phenomena was utilized as a pore-forming agent. ► Cyclic dilation behavior was investigated with an in situ electrochemical dilatometry. ► PMMA-treated electrodes exhibited improved cycle performance. ► Control of electrode porosity by PMMA can be an effective way for Si-based electrodes.