Researchers Achieve Storage Technology Breakthrough for Grid Storage

Scientists at the University of Adelaide have unveiled a major advancement in energy storage technology by developing a high-performance dry electrode for aqueous zinc–iodine batteries. The new electrode design more than doubles the performance of conventional lithium-ion and iodine cathodes, offering a low-cost, environmentally safe, and scalable alternative for large-scale energy storage.

The breakthrough, led by Professor Shizhang Qiao, Director of the Centre for Materials in Energy and Catalysis, involves creating dense, self-supporting dry electrodes by compressing dry powdered materials—an approach that enhances energy retention and lifespan.

Tackling Dendrites and Stability Challenges

A key innovation in the new storage technology lies in the addition of a simple compound, 1,3,5-trioxane, to the electrolyte. This triggers the formation of a flexible, protective film on the zinc surface during battery charging. The film acts as a barrier against dendrites, needle-like structures that can grow during charging and risk short-circuiting the battery.

“This film effectively suppresses dendrite formation, which has long been a barrier to making aqueous zinc batteries commercially viable,” said Qiao.

Performance That Rivals Lithium-Ion

While aqueous zinc–iodine batteries are already lauded for their safety, affordability, and abundance of materials, their performance has lagged behind lithium-ion systems. However, the new electrode formulation changes that.

“The technique resulted in a record-high active material loading of 100 mg/sq cm,” said Han Wu, PhD candidate and research associate at the university. The team reported that pouch cells retained 88.6 percent of their capacity after 750 cycles, while coin cells showed a remarkable 99.8 percent retention over 500 cycles.

Synchrotron infrared imaging confirmed how the protective film formed in real-time, highlighting its role in stabilizing the zinc interface and maintaining battery integrity over extended use.

A Step Forward for Grid-Scale Energy Storage

The new storage technology offers a dense electrode structure which also reduces self-discharge and mitigates shuttle loss by minimising iodine leakage into the electrolyte - a common issue in aqueous systems. With enhanced cycle life, safety, and energy density, the researchers believe the innovation makes zinc–iodine batteries a compelling option for grid-scale and renewable energy storage.

“The technology is particularly promising for utilities, microgrids, and energy providers that need affordable, long-lasting storage solutions,” Qiao said.

Looking Ahead: Scalable, Industrial-Ready Tech

The team plans to scale the technology using industrial roll-to-roll manufacturing techniques. By using lighter current collectors and optimising the electrolyte ratio, they project the energy density could reach up to 90 Wh/kg - doubling the current benchmark of around 45 Wh/kg.

With a growing need for cost-effective and sustainable storage technology options in the energy transition, this innovation marks a pivotal moment for aqueous battery technologies.