In the pursuit of meeting our climate targets and achieving a seamless transition to renewable energy sources, we encounter a formidable obstacle: the need for efficient and sustainable energy storage, especially when relying on intermittent sources like solar and wind power. However, a beacon of hope emerges from Germany, where a research consortium led by Fraunhofer IZM has set its sights on tackling this challenge through groundbreaking zinc battery technology.
This remarkable innovation not only facilitates the storage of electrical power but also has the unique capability of producing green hydrogen on demand. To realize this ambitious vision, the research institutions have joined forces with two commercial partners, Zn2H2 and Steel PRO Maschinenbau, forming the Zn-H2 project.
A truly new technology
Diverging from conventional lithium-ion batteries, the group chose to explore the potential of zinc batteries due to their economic advantages and the use of fully-recyclable and readily available materials: steel, zinc, and potassium hydroxide. The integration of alkaline water electrolysis into this battery composition resulted in a truly new technology.
Dr. Robert Hahn from Fraunhofer IZM provided insight into the chemical processes that take place within the battery:
“During charging, water oxidizes into oxygen while simultaneously reducing the zinc oxide to metallic zinc. Upon discharge, the zinc returns to its oxide state, and the water is once again reduced, releasing hydrogen. This intricate combination effectively marries the attributes of a standard battery with the functionality of a hydrogen source.”
Lab tests on individual battery cells have already been conducted to assess their efficiency and stability over multiple cycles, affirming the success of their innovative system. The team now sets its sights on testing eight interconnected cells, each boasting a capacity of approximately 12V and 50Ah, by the year’s end.
Anticipated results indicate promising figures, with an expected 50% efficiency in power storage and an impressive 80% efficiency in hydrogen production, all while offering an estimated life expectancy of a decade for the system.
Looking to the future, the researchers envision an industrially-scalable, electrically rechargeable hydrogen storage system that serves a dual purpose: storing energy as metallic zinc and converting it back into electrical power and hydrogen as needed. Furthermore, the cost-effectiveness of zinc batteries renders this technology an appealing and viable alternative for commercial green energy storage.
The key to decarbonizing high-emission industries
With the Zn-H2 project slated to conclude in September 2025, it seeks to make substantial strides in facilitating our transition to green energy.
Unlocking the full potential of green hydrogen, which currently comprises a mere 1% of global hydrogen production, holds the key to decarbonizing high-emission industries, including chemicals and steel manufacturing, while also providing electricity and heat for domestic consumption. We are excited about the possibilities ahead!