A Comprehensive Review of Energy Storage Batteries for Solar Energy Systems

Abstract

Solar energy intermittency necessitates efficient energy storage for grid stability and reliable power supply. This review comprehensively examines battery technologies for solar photovoltaic applications, including lead-acid, lithium-ion (LFP, NMC, LTO), flow batteries (vanadium redox, zinc-bromine), and emerging systems such as sodium-ion, solid-state, and saltwater batteries. We evaluate performance characteristics—energy density, cycle life, round-trip efficiency, depth of discharge alongside cost-effectiveness, thermal management requirements, environmental impact, and application suitability across off-grid, residential, and utility-scale installations. Lithium-ion batteries currently offer optimal balance of efficiency (90–95%) and lifespan (2000–6000 cycles), while flow batteries provide exceptional scalability for long-duration storage. Lead-acid remains cost-effective for low-budget systems despite limited cycle life. Critical challenges include degradation mechanisms, thermal runaway risks, recycling infrastructure, and upfront capital costs. Emerging trends second-life EV batteries, AI-optimized management, hybrid supercapacitor integration, and sustainable material innovation are shaping future deployment. This synthesis guides researchers, policymakers, and industry stakeholders toward techno-economically viable and environmentally sustainable solar energy storage solutions.