A review of electro-hydrogen synergistic systems: from key material breakthroughs, multi-timescale control to...

Under the carbon peaking and carbon neutrality targets, electro-hydrogen synergetic systems have emerged as a promising pathway for cross-temporal energy conversion and deep decarbonization across power, transport, and industrial sectors via the electricity-hydrogen-electricity. The system can enhance renewable energy integration, improve grid resilience, and support low-carbon transitions in hard-to-abate sectors. However, their large-scale deployment is still constrained by bottlenecks in key materials, efficiency coordination, dynamic matching, safety, and techno-economic performance. The review develops a framework spanning materials, components, systems, and market applications, with a focus on key material innovation, multi-timescale regulation, and full-chain integration. First, recent advances and critical challenges in water electrolysis technologies, including PEM, ALK, AEM, and SOEC, are reviewed in terms of catalyst materials, membrane electrode structures, stack-level in situ diagnostics, and durability under fluctuating operating conditions. Second, high-pressure gaseous, cryogenic liquid, and solid-state hydrogen storage pathways are comparatively assessed, revealing trade-offs among energy density, efficiency loss, safety, cost, and infrastructure compatibility. Third, the review summarizes coupling architectures for electricity-hydrogen-heat-gas multi-energy systems, as well as dynamic response control and multi-timescale optimal scheduling from microgrids and industrial parks to regional integrated energy systems. Finally, the application potential of electro-hydrogen synergetic systems in renewable energy consumption, grid ancillary services, and industrial decarbonization is discussed, and key scientific questions and suggestions for large-scale demonstration and commercialization are proposed.