An Overview of Application-orientated Multifunctional Large-scale Stationary Battery and Hydrogen Hybrid Energy Storage System

The imperative to address traditional energy crises and environmental concerns has accelerated the need for energy structure transformation. However, the variable nature of renewable energy poses challenges in meeting complex practical energy requirements. To address this issue, the construction of a multifunctional large-scale stationary energy storage system is considered an effective solution. This paper critically examines the battery and hydrogen hybrid energy storage systems. Both technologies face limitations hindering them from fully meeting future energy storage needs, such as large storage capacity in limited space, frequent storage with rapid response, and continuous storage without loss. Batteries, with their rapid response (90%), excel in frequent short-duration energy storage. However, limitations such as a selfdischarge rate (>1%) and capacity loss (~20%) restrict their use for long-duration energy storage. Hydrogen, as a potential energy carrier, is suitable for large-scale, long-duration energy storage due to its high energy density, steady state, and low loss. Nevertheless, it is less efficient for frequent energy storage due to its low storage efficiency (~50%). Ongoing research suggests that a battery and hydrogen hybrid energy storage system could combine the strengths of both technologies to meet the growing demand for large-scale, long-duration energy storage. To assess their applied potentials, this paper provides a detailed analysis of the research status of both energy storage technologies using proposed key performance indices. Additionally, application-oriented future directions and challenges of the battery and hydrogen hybrid energy storage system are outlined from multiple perspectives, offering guidance for the development of advanced energy storage systems.