Flow batteries are regarded as one of the most promising energy storage technologies for stationary large-scale storage because the power capability and the energy storage capability of these storage systems can be sized independently, which benefits load balancing, peak shaving, power conversion and stand-alone power system. As an emerging rechargeable battery technology, lithium redox flow batteries (Li-RFB) represent an important advance which is distinct from conventional solid-state rechargeable batteries. Researchers have now demonstrated an all-metallocene-based non-aqueous redox flow battery with stable cycling performance and comparable energy density with current related energy storage technologies.