Large batteries capable of storing solar and wind energy for extended periods are essential for successfully integrating these renewable sources into the U.S. power grid. However, the current options for safe and dependable battery technologies to facilitate the transition to sustainable energy are limited. Recently, researchers have developed a cost-effective and eco-friendly aluminum-ion (Al-ion) battery that may address this issue.
Large batteries capable of storing solar and wind energy for extended periods are essential for integrating these abundant renewable sources into the U.S. power grid. Despite this need, there is a shortage of safe and dependable battery technologies to support the shift toward clean, sustainable energy. Researchers have now created a cost-effective and eco-friendly aluminum-ion (Al-ion) battery that could meet these requirements.
Lithium-ion (Li-ion) batteries are commonly found in many consumer devices, such as power tools and electric vehicles, thanks to their high energy density. However, the high cost of lithium makes it impractical for the large-scale battery systems required for utility energy storage, and the flammability of Li-ion batteries presents serious safety concerns. Rechargeable Al-ion batteries serve as a potential alternative for long-term energy storage. Yet, their most frequently used electrolyte, liquid aluminum chloride, tends to corrode the aluminum anode and is highly susceptible to moisture, which worsens corrosion. These issues lead to poor stability and a reduction in electrical performance over time. To address these limitations, researchers Wei Wang, Shuqiang Jiao, and their team set out to create a better Al-ion battery.
The researchers incorporated an inert aluminum fluoride salt into an electrolyte containing Al-ion, transforming it into a solid-state electrolyte. The aluminum fluoride salt features a 3D porous structure that facilitates the movement of aluminum ions across the electrolyte, enhancing conductivity. Furthermore, when assembling their Al-ion battery, the team applied fluoroethylene carbonate as an interface additive, forming a thin solid layer on the electrodes, which helps prevent the buildup of aluminum crystals that can harm battery performance.
Experimental results showed significant improvements in moisture resistance, physical stability, and thermal durability. The battery was able to endure repeated punctures from sharp objects and function at temperatures up to 392 degrees Fahrenheit. Impressively, this solid-state Al-ion battery demonstrated remarkable longevity, surviving 10,000 charge-discharge cycles while maintaining over 99% of its initial capacity. Additionally, a majority of the aluminum fluoride could be easily recovered with a simple wash and reused in another battery, albeit with slightly reduced performance. This innovation has the potential to decrease the production costs of Al-ion batteries while prolonging their lifespan, making them more feasible for use.
According to Wang, “This new Al-ion battery design demonstrates the possibility of a long-lasting, cost-efficient, and safe energy storage solution. The capability to retrieve and recycle crucial materials enhances the sustainability of the technology.” The researchers also note that additional advancements in energy density and life cycle are necessary before the battery can be commercially available.
The authors express gratitude for funding received from the National Natural Science Foundation of China, the Beijing Nova Program, and the Interdisciplinary Research Project for Young Teachers of the University of Science and Technology Beijing.
