Exploring innovative materials for supercapacitors has been a focus to broaden energy storage alternatives. The distinctive properties and applications of solid-solution MXenes have garnered significant attention in this regard. This research delves into the application of solid-solution MXene materials in supercapacitor energy storage, examining aspects such as manufacturing, electrochemical behaviour, and structural characteristics. The article begins with an overview of the MXene family, highlighting its potential for energy storage, a highly sought-after quality. The solid-solution approach is particularly favoured for its ability to enhance MXenes electrochemical properties by introducing additional components. This study explores how etching, and intercalation impact the material’s structure and energy storage capabilities. Detailed analyses of the crystallographic, surface chemical, and morphological properties of solid-solution MXenes are conducted. The study emphasizes the influence of these factors on the electrochemical performance of MXene supercapacitors, stressing the importance of tailored design. The research extensively investigates the durability, electrical storage capacity, and charge retention mechanisms of these materials. Understanding the effects of dopants and intercalants on charge storage dynamics could lead to improvements in MXene electrode energy storage. The paper reviews the current advancements, challenges, and the potential of solid-solution MXenes in supercapacitors. With a careful examination of existing research and strategic selection of constituents, solid-solution MXene materials could play a crucial role in future energy storage systems, providing a valuable tool for engineers and scientists exploring renewable energy storage technologies.