Beyond Li-Batteries
Our current research focuses on advancing beyond-lithium batteries, including primary silicon-air and titanium-air systems as well as secondary zinc-air and iron-air technologies. Silicon-air batteries address challenges like anode passivation and corrosion through surface modifications and additives. Titanium-air batteries utilize non-aqueous ionic liquid electrolytes, offering potential for high capacities despite titanium's natural passivity. Secondary zinc-air and iron-air batteries focus on improving the performance through electrode and electrolyte additives, making them the most advanced rechargeable metal-air systems. Through innovations in materials and electrolytes, we aim to deliver sustainable, high-energy-density solutions for future energy storage applications.
Silicon-Air Batteries
Silicon-air batteries are a primary energy storage technology, advantageous due to the abundance and high theoretical specific capacity of silicon. These batteries are particularly important for low-power applications, such as transient electronics, where sustainability and efficiency are critical. However, challenges like silicon anode passivation and corrosion have hindered their practical use. We tackled these issues by developing advanced surface modification techniques and specially designed electrolytes. Through these innovations, we significantly enhanced the stability and operational life of silicon-air batteries.1
Titanium-Air Batteries
Titanium-air batteries are a primary energy storage technology, offering the potential for multi-electron transfer and high energy capacities. This system is essential for pushing the boundaries of energy storage efficiency. Yet, titanium's natural passivity has long been a challenge, limiting its reactivity. We addressed this by utilizing a novel non-aqueous ionic liquid electrolyte and optimizing electrochemical parameters. These solutions have unlocked the path to harness the titanium’s full potential, enabling reliable and high-capacity performance.1
Zinc-Air Batteries
Zinc-air batteries stand out as one of the most promising metal-air systems, combining high theoretical energy densities with resource efficiency and safety and an immense potential for large-scale applications. However, challenges such as dendrite formation, air cathode degradation, and electrolyte instability hinder their commercial scalability. To address these hurdles, we have developed Al-Zn alloy anodes 1 and focused our research on neutral and near-neutral electrolytes enhanced with chelating additives like ethylenediaminetetraacetic acid (EDTA) 2. EDTA effectively prevents the formation of insoluble zinc hydroxides and oxides, promoting homogeneous zinc deposition and significantly improving discharge voltages and enhanced cycling performance. Furthermore, operando studies using advanced imaging techniques, such as laboratory X-ray computed tomography, have provided new insights into electrode morphology evolution during cycling 3. These methods reveal how our electrolyte formulations suppress dendrite growth and extend electrode stability under realistic operating conditions.
Iron-Air Batteries
Iron-air batteries are a promising alternative among metal-air systems due to iron's low dendrite formation, high volumetric energy (9,700 Wh/LFe), and abundance as the second most common metal on Earth, with an annual production of 2.5 billion tons. Despite commercialization attempts in the 1970s, challenges such as iron corrosion in aqueous electrolytes, hydrogen evolution, and the low conductivity of Fe(OH)₂ have limited their adoption. To address these issues, ongoing efforts focus on developing novel electrodes with optimized compositions to enhance cyclability and specific capacity, as well as refining operating conditions 1. Advanced in-situ characterization methods, such as Atomic Force Microscopy 2 and Gas Chromatogrphy 3 are also being employed to gain deeper insights into the fundamental mechanisms at play, leading further improvements in performance.
Further information at FeEnCap.
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Last Modified: 09.02.2025