Review on Molybdenum-Based Negative Electrodes for High-Performance Supercapacitors

Supercapacitors (SCs) are promising energy storage devices known for their high power density, long cycle life, and environmental sustainability. Among the key components, electrode materials play a pivotal role in determining the device performance. While extensive efforts have been devoted to enhance energy density through the development of positive electrode materials in asymmetric configurations, the exploration of negative electrode materials remains comparatively underdeveloped. In recent years, molybdenum-based materials have emerged as attractive candidates for negative electrodes due to their favorable crystal structures, high theoretical capacities, ease of synthesis, and low toxicity. This mini-review provides a focused overview of recent advances in molybdenum-based negative electrode materials for both asymmetric and symmetric SC systems. It highlights progress in the design and electrochemical evaluation of pure nanostructured molybdenum materials, vacancy- and dopant-engineered derivatives, and various nanocomposites. Special emphasis is placed on their synthesis strategies, structural features, and charge storage mechanisms. The review also discusses existing challenges and outlines future research directions to accelerate the development of high-performance molybdenum-based SC electrodes. Ultimately, this work aims to inform ongoing research and support the integration of these materials into next-generation energy storage technologies.