This review discusses recent progress and challenges in flexible electrochemical energy storage devices (EES) and their applications in wearable electronics. The focus is on the design of components such as electrode materials, gel electrolytes, and separators to develop high-performance, deformable energy storage systems. The review begins with an overview of carbon-based and conductive polymer materials used in flexible EES, followed by a summary of their fabrication and optimization strategies. It then presents a comprehensive review of the applications of these materials in supercapacitors, lithium-ion batteries, and zinc-ion batteries. Finally, the review outlines challenges and future directions for next-generation flexible EES. Flexible EES must maintain mechanical and electrochemical performance under repeated deformation. Traditional components, such as electrodes and electrolytes, are not suitable for this, so all components must be selected to withstand continuous deformation. Electrodes and electrolytes are critical in determining the mechanical and electrochemical properties of the system. The review discusses various strategies for designing flexible electrodes, including structural engineering and combining active materials with flexible substrates. Examples include carbon nanotube arrays with gradient structures, MXene/rGO composites, and helix-inspired battery designs. Flexible hydrogel electrolytes are also crucial for EES due to their mechanical stability and conductivity. The review highlights the development of ion-gel and hydrogel electrolytes that enhance cycling stability and mechanical properties. For instance, a water-deficient hydrogel electrolyte was developed to improve ion conductivity and long-term stability. Flexible supercapacitors (SCs) are promising for wearable electronics due to their high power density, long cycle life, and fast charge/discharge rates. The review discusses various flexible electrode materials, including compressible, foldable, and stretchable electrodes. Examples include carbon aerogels, graphene-based electrodes, and hydrogel electrodes with exceptional mechanical flexibility and electrochemical performance. Flexible zinc-ion batteries (ZIBs) are also explored due to their safety, cost-effectiveness, and simplified assembly. The review discusses various cathode materials, such as manganese oxides and vanadium oxides, and their integration with flexible substrates. The development of flexible anodes, including bionic honeycomb structures and Zn powder-based electrodes, is also highlighted to address dendrite growth and improve cycling stability. Overall, the review emphasizes the importance of material design and structural optimization in achieving high-performance, deformable EES for wearable electronics. Challenges such as dendrite growth, interfacial adhesion, and mechanical stability are discussed, along with future directions for next-generation flexible EES.This review discusses recent progress and challenges in flexible electrochemical energy storage devices (EES) and their applications in wearable electronics. The focus is on the design of components such as electrode materials, gel electrolytes, and separators to develop high-performance, deformable energy storage systems. The review begins with an overview of carbon-based and conductive polymer materials used in flexible EES, followed by a summary of their fabrication and optimization strategies. It then presents a comprehensive review of the applications of these materials in supercapacitors, lithium-ion batteries, and zinc-ion batteries. Finally, the review outlines challenges and future directions for next-generation flexible EES. Flexible EES must maintain mechanical and electrochemical performance under repeated deformation. Traditional components, such as electrodes and electrolytes, are not suitable for this, so all components must be selected to withstand continuous deformation. Electrodes and electrolytes are critical in determining the mechanical and electrochemical properties of the system. The review discusses various strategies for designing flexible electrodes, including structural engineering and combining active materials with flexible substrates. Examples include carbon nanotube arrays with gradient structures, MXene/rGO composites, and helix-inspired battery designs. Flexible hydrogel electrolytes are also crucial for EES due to their mechanical stability and conductivity. The review highlights the development of ion-gel and hydrogel electrolytes that enhance cycling stability and mechanical properties. For instance, a water-deficient hydrogel electrolyte was developed to improve ion conductivity and long-term stability. Flexible supercapacitors (SCs) are promising for wearable electronics due to their high power density, long cycle life, and fast charge/discharge rates. The review discusses various flexible electrode materials, including compressible, foldable, and stretchable electrodes. Examples include carbon aerogels, graphene-based electrodes, and hydrogel electrodes with exceptional mechanical flexibility and electrochemical performance. Flexible zinc-ion batteries (ZIBs) are also explored due to their safety, cost-effectiveness, and simplified assembly. The review discusses various cathode materials, such as manganese oxides and vanadium oxides, and their integration with flexible substrates. The development of flexible anodes, including bionic honeycomb structures and Zn powder-based electrodes, is also highlighted to address dendrite growth and improve cycling stability. Overall, the review emphasizes the importance of material design and structural optimization in achieving high-performance, deformable EES for wearable electronics. Challenges such as dendrite growth, interfacial adhesion, and mechanical stability are discussed, along with future directions for next-generation flexible EES.