This summer has witnessed unprecedented heat waves and heavy rainfall, underscoring the urgency of developing renewable energy sources and their associated infrastructure to ensure our planet’s sustainability during times of crisis. However, there are clear limitations to relying on renewables, primarily due to the volatility of electricity production, which is heavily influenced by unpredictable factors such as weather conditions.
To address this issue, there is a growing demand for energy storage systems (ESS) capable of storing and supplying electricity as needed. Unfortunately, the current use of lithium-ion batteries (LIBs) in ESS poses several problems. Not only are they expensive, but they also carry the risk of potential fires. Therefore, there is an urgent need for more affordable and safer alternatives.
A research team led by Dr. Oh, Si Hyoung at the Energy Storage Research Center of the Korea Institute of Science and Technology (KIST) has made significant progress by developing a highly safe, aqueous, rechargeable battery. This innovation could serve as a cost-effective and secure replacement for LIBs. Their findings have been published in the journal Energy Storage Materials.
Aqueous rechargeable batteries have a significant economic advantage due to their lower raw material costs compared to LIBs. However, they face a common challenge - the generation of hydrogen gas from water decomposition, which gradually increases internal pressure and can lead to electrolyte depletion, thus jeopardizing battery safety and commercialization prospects.
Researchers have previously attempted to address this issue by adding a surface protection layer to reduce contact between the metal anode and the electrolyte. Unfortunately, corrosion of the metal anode and water decomposition in the electrolyte remains a concern, with the ongoing accumulation of hydrogen gas potentially causing problems during long-term operation.
To tackle this critical issue, the research team has introduced a composite catalyst comprising manganese dioxide and palladium. This catalyst can automatically convert the hydrogen gas generated inside the cell into water, ensuring both performance and safety.
Manganese dioxide alone does not typically react with hydrogen gas, but when a small amount of palladium is added, the catalysts readily absorb and regenerate hydrogen into water. In their prototype cell with the new catalysts, the internal pressure remained well below safety limits, and there was no observable electrolyte depletion.
The results of this research represent a significant step in addressing one of the major safety concerns associated with aqueous batteries, making them a viable option for future commercial applications in energy storage systems. Replacing expensive and potentially risky LIBs with more affordable and secure aqueous batteries could spur rapid growth in the global energy storage market.
Dr. Oh, Si Hyoung of KIST stated, “This technology introduces a tailored safety approach for aqueous rechargeable batteries, featuring a built-in active safety mechanism that automatically controls risk factors. Furthermore, it has broader applications in various industrial facilities where hydrogen gas leakage is a significant safety concern, such as hydrogen gas stations and nuclear power plants, to enhance public safety.”