The demand for energy continues to rise globally, accompanied by growing concerns over climate change and the depletion of finite fossil fuel resources. In response, there has been a concerted effort to transition towards sustainable energy systems, with renewable energy sources playing a central role. However, the intermittent nature of renewables, like solar or wind, presents significant challenges for grid stability and reliability. Energy storage technologies represent a cutting-edge field within sustainable energy systems, offering a promising solution by enabling the capture and storage of excess energy during periods of low demand for later use, thereby smoothing out fluctuations in supply and demand.

Despite the rapid progress in energy storage technologies, several challenges remain that hinder their widespread adoption and integration into existing energy infrastructure. One key challenge is the cost-effectiveness and scalability of energy storage systems, particularly for grid-scale applications. Additionally, issues related to the efficiency, lifespan, and safety of energy storage technologies need to be addressed to ensure their long-term viability. Furthermore, the lack of standardized regulatory frameworks and policies, as well as uncertainties surrounding market incentives, pose barriers to investment and the deployment of energy storage solutions. Overcoming these challenges requires interdisciplinary collaboration among researchers, engineers, policymakers, and industry stakeholders to develop innovative solutions and create an enabling environment for energy storage deployment.

This Special Issue aims to explore the latest advancements, trends, challenges, and applications of energy storage technologies, emphasizing their global impact and importance and providing a comprehensive overview of advanced energy storage technologies and their role in accelerating the transition to sustainable energy systems. By highlighting recent technological advancements, economic analysis, regulatory challenges, and real-world applications, we aim to demonstrate the topic's relevance and urgency, facilitate knowledge exchange, and contribute to the development of innovative solutions. We welcome both original research and review articles.

Potential topics include but are not limited to the following:

• Phase change materials, and other thermal storage mediums for heat and cold storage
• Battery technologies
• Advancements in lithium-ion batteries
• Pumped hydro and compressed air energy storage
• Advances in hydrogen storage materials and technologies
• Polymer electrolyte membrane fuel cells and solid oxide fuel cells
• Grid-scale energy storage and virtual power plants
• Economic analysis of energy storage technologies
• Regulatory frameworks and policies for energy storage
• Real-world applications and case studies of energy storage systems
• Smart grid integration and the role of energy storage.