This electrochemical quartz crystal microbalance (EQCM) cell is designed for in situ monitoring of mass changes at electrode surfaces during electrochemical processes. Compatible with specific crystal oscillators (CHI400C or SRS-QCM200, depending on model), it integrates a three-electrode configuration featuring a customer-provided working electrode, a platinum wire counter electrode, and a silver chloride reference electrode. The cell enables simultaneous gravimetric and electrochemical measurements, making it particularly relevant for studying electrode reactions, adsorption/desorption phenomena, and thin-film formation in energy materials and analytical electrochemistry. Common applications include battery material characterization, corrosion studies, and sensor development, where precise mass–charge correlation is essential. Manufactured by Tianjin Aida, three model variants (W101, W102, W103) accommodate different QCM instruments while maintaining consistent electrochemical performance.