Retains capacity after thousands of cycles with improved safety, sustainability, and affordability.

Researchers have developed an aluminum-ion battery that outperforms lithium-ion in longevity, safety, and sustainability, retaining capacity after thousands of charge cycles. By incorporating a solid-state electrolyte, this innovation curtails the fire hazards and resource constraints associated with Lithium-ion technology while offering a cost-effective and recyclable solution tailor-made for large-scale energy storage.

In a press release by the American Chemical Society , the research team revealed the goal of an environmentally friendly aluminum-ion battery design: "Large batteries for long-term storage of solar and wind power are key to integrating abundant and renewable energy sources into the U.S. power grid. However, there is a lack of safe and reliable battery technologies to support the push toward sustainable, clean energy."

Building a better battery

Picture a battery that lasts for decades, charges safely, and competes with lithium-ion at a fraction of the price. The solid-state aluminum-ion battery has an exceptionally long life, losing less than 1% of its original capacity after 10,000 charge-discharge cycles.

"This new Al-ion design shows the potential for long-lasting, cost-effective, and high-safety energy storage system," said Wei Wang, study co-author. "The ability to recover and recycle key materials makes the technology more sustainable."

"Potential substitutes for reliable long-term energy storage systems include rechargeable Al-ion batteries," the release pointed out. "However, their most common electrolyte, liquid aluminum chloride, corrodes the aluminum anode and is highly sensitive to moisture, which exacerbates the corrosion. Both factors contribute to poor stability and a decline in electrical performance over time."

Wei Wang, Shuqiang Jiao, and their team of researchers set out to design an improved aluminum-ion battery without these limitations. By leveraging aluminum, a more abundant and less expensive material, aluminum-ion battery chemistry offers a combination of high efficiency, stability, and affordability, making it a promising candidate for replacing conventional lithium-ion batteries in a number of applications. The trick was to solve for corrosion.

"The team added an inert aluminum fluoride salt to an Al-ion-containing electrolyte, turning it into a solid-state electrolyte. Additionally, when the researchers constructed their Al-ion battery, they used fluoroethylene carbonate as an interface additive to create a thin solid coating on the electrodes to prevent the formation of aluminum crystals that degrade battery health."

Longevity and safe performance

ACS

Aluminum fluoride salt produces a solid-state electrolyte that enhances aluminum-ion transport, improving performance and longevity.

Lithium-ion batteries, widely used in electronics and electric vehicles, face challenges as large-scale energy storage solutions due to high costs, resource scarcity, and safety concerns.

One of the most remarkable features of this battery is its longevity. Testing showed the battery far outlasts conventional lithium-ion batteries, which typically degrade after a few thousand cycles. (As a rule, electric vehicle lithium-ion battery capacity drops significantly between five and 10 years and needs replacing; most car manufacturers offer warranties to that effect.)

The aluminum-ionbattery's extended lifespan reduces replacement frequency and costs for consumers and industries, making it ideal for large-scale and grid-scale energy storage, where batteries must maintain a consistent capacity, operating reliably over the years to justify the investment.

The newly developed aluminum-ion battery addresses these concerns by offering superior safety features; its chemistry improves structural integrity and enhances aluminum-ion transport for efficient charge transfer, and due to its solid electrolyte, the battery is resistant to moisture and has improved physical and thermal stability, making it far less prone to dangerous failures.

"In experiments, the battery's moisture resistance as well as physical and thermal stability were enhanced, allowing it to withstand repeated jabs from a sharp object and temperatures as high as 392 degrees Fahrenheit," the press release said.

This resilience makes it an attractive option for critical applications where battery safety is paramount, such as energy storage for homes, businesses, and even industrial-scale power systems. The drop in production expense could also accelerate the adoption of next generation large-scale battery storage.

Lithium battery chemistries are expensive to manufacture, rely on potentially harmful mining practices, and have made headlines with safety concerns related to thermal runaway and fire risks. These drawbacks make lithium-ion batteries less than ideal for long-term, grid-scale energy storage.

Designed with sustainability in mind, most aluminum fluoride used in the electrolyte can be recovered and recycled with a simple wash, enabling reuse with minimal performance loss. If successfully scaled, this breakthrough could revolutionize renewable energy storage, making it affordable and safe to implement solar and wind energy at grid-scale.