This study investigates the charge storage mechanism of reduced graphene oxide (rGO) in aqueous electrolytes, focusing on the role of cation desolvation in enhancing capacitance. Using a combination of cavity micro-electrode, operando electrochemical quartz crystal microbalance (EQCM), and operando electrochemical dilatometry (ECD), the researchers identified two distinct regions of charge storage, depending on cation-carbon interactions. In region II, under high cathodic polarization, a significant capacitance increase was observed in Zn²⁺-containing electrolytes with minimal volume expansion, attributed to Zn²⁺ desolvation due to strong electrostatic interactions with rGO. These findings highlight the importance of ion-electrode interaction strength and cation desolvation in modulating charge storage mechanisms, offering potential pathways for optimizing capacitive energy storage. The study also explores the electrochemical behavior of rGO in three different electrolytes (LiCl, MgCl₂, and ZnCl₂), revealing cation-dependent charge storage mechanisms. EQCM and ECD measurements showed that cation desolvation during cathodic polarization leads to enhanced capacitance, with Zn²⁺ exhibiting the most significant enhancement due to its strong interaction with rGO. The results suggest that cation desolvation allows for more efficient charge screening and storage, leading to improved electrochemical performance. The study emphasizes the importance of understanding confined electrochemical systems and the coupling between chemical, electrochemical, and transport processes in confinement for future applications in energy, catalysis, and water treatment. The findings provide insights into the complex interplay between ion-electrode interactions and charge storage mechanisms in 2D materials, highlighting the potential for tailored electrolyte and electrode design to optimize capacitive charge storage for high-performance energy storage systems.This study investigates the charge storage mechanism of reduced graphene oxide (rGO) in aqueous electrolytes, focusing on the role of cation desolvation in enhancing capacitance. Using a combination of cavity micro-electrode, operando electrochemical quartz crystal microbalance (EQCM), and operando electrochemical dilatometry (ECD), the researchers identified two distinct regions of charge storage, depending on cation-carbon interactions. In region II, under high cathodic polarization, a significant capacitance increase was observed in Zn²⁺-containing electrolytes with minimal volume expansion, attributed to Zn²⁺ desolvation due to strong electrostatic interactions with rGO. These findings highlight the importance of ion-electrode interaction strength and cation desolvation in modulating charge storage mechanisms, offering potential pathways for optimizing capacitive energy storage. The study also explores the electrochemical behavior of rGO in three different electrolytes (LiCl, MgCl₂, and ZnCl₂), revealing cation-dependent charge storage mechanisms. EQCM and ECD measurements showed that cation desolvation during cathodic polarization leads to enhanced capacitance, with Zn²⁺ exhibiting the most significant enhancement due to its strong interaction with rGO. The results suggest that cation desolvation allows for more efficient charge screening and storage, leading to improved electrochemical performance. The study emphasizes the importance of understanding confined electrochemical systems and the coupling between chemical, electrochemical, and transport processes in confinement for future applications in energy, catalysis, and water treatment. The findings provide insights into the complex interplay between ion-electrode interactions and charge storage mechanisms in 2D materials, highlighting the potential for tailored electrolyte and electrode design to optimize capacitive charge storage for high-performance energy storage systems.