Calcium-Ion Breakthrough Could Replace Lithium in Future Batteries

Scientists at The Hong Kong University of Science and Technology (HKUST) have made a breakthrough in battery technology. A team led by Professor Yoonseob Kim has developed a new calcium-ion battery (CIB) system using quasi-solid-state electrolytes. Their findings, published in Advanced Science, suggest a promising alternative to traditional lithium-ion batteries.

The research focused on creating a CIB system that could rival lithium-ion performance. Tests showed the battery achieved a reversible capacity of 155.9 mAh g⁻¹ at 0.15 A g⁻¹. Even after 1,000 charge-discharge cycles at 1 A g⁻¹, it retained over 74.6% of its original capacity, indicating strong durability.

The quasi-solid-state electrolytes (QSSEs) played a key role in the battery's efficiency. At room temperature, they reached an ionic conductivity of 0.46 mS cm⁻¹ and a calcium-ion transport capability exceeding 0.53. These results highlight the system's potential for long-term reliability and fast charging.

While the technology shows promise, no car manufacturers or energy companies have yet announced plans to adopt it. The team's work also notes that regulatory approval and market acceptance could take time. Still, the findings open doors for applications in electric vehicles and renewable energy storage.

Professor Kim's group emphasised the sustainability benefits of calcium-ion batteries. Unlike lithium, calcium is more abundant and less costly, making it an attractive option for future energy solutions. The study suggests this innovation could eventually reshape how we store and use power in everyday devices and infrastructure.

The HKUST research marks a significant step forward in battery technology. With its high capacity retention and efficient ion transport, the calcium-ion system could offer a greener, more sustainable alternative to lithium-ion batteries. However, real-world adoption will depend on further testing, industry interest, and overcoming existing market barriers.