Materials and technologies for energy storage: Status, challenges, and opportunities

Decarbonizing our carbon-constrained energy economy requires massive increase in renewable power as the primary electricity source. However, deficiencies in energy storage continue to slow down rapid integration of renewables into the electric grid. Currently, global electrical storage capacity stands at an insufficiently low level of only 800 GWh, compared to nearly 10,000 GWh of storage capability that would otherwise be needed to provide 4 h of storage for the world’s > 2500 GW of installed renewable power generation capacity. As specific requirements for energy storage vary widely across many grid and non-grid applications, research and development efforts must enable diverse range of storage technologies and materials that offer complementary strengths to assure energy security, flexibility, and sustainability. Materials discovery and innovation will be key to achieve these objectives. This article provides an overview of electrical energy-storage materials, systems, and technologies with emphasis on electrochemical storage. Graphical Abstract