Repurposing Electric Vehicle Batteries for Stationary Energy Storage: A Comprehensive Analysis of Second-Life Applications and Vehicle-to-Grid Integration

The rapid global adoption of electric vehicles presents both opportunities and challenges for sustainable energy systems. As lithium-ion batteries in electric vehicles typically retain 70-80% of their original capacity after automotive retirement, significant potential exists for repurposing these batteries in stationary energy storage applications. This paper examines the technical, economic, and environmental dimensions of second-life battery deployment, including integration with renewable energy systems and vehicle-to-grid technologies. Analysis of current implementations reveals that second-life batteries can achieve cost reductions of 30-70% compared to new battery systems while contributing to circular economy principles. The paper presents case studies demonstrating successful integration with solar photovoltaic systems for residential off-grid applications, discusses technical challenges including battery management system compatibility and thermal considerations, and projects that global second-life battery capacity could reach 200-350 gigawatt-hours by 2030. Findings indicate that strategic deployment of retired electric vehicle batteries can significantly enhance grid resilience, facilitate renewable energy integration, and reduce primary material demand while addressing the growing challenge of end-of-life battery management.