Slime-Like Electrolyte Could Make Lithium-Ion Batteries Safer, Faster, and Fully Recyclable

 Researchers at the Institute of Science Tokyo have developed a new slime-like electrolyte that could reshape how lithium-ion batteries are made, used, and recycled. The material, called 3D-SLISE (3D-Slime Interface Quasi-Solid Electrolyte), combines high performance with safety and environmental benefits, offering solutions to several long-standing challenges in the battery industry.

Lithium-ion batteries are central to modern technology, powering smartphones, laptops, and electric vehicles. But despite their success, they rely on flammable organic solvents, require energy-intensive manufacturing, and are difficult to recycle efficiently. These weaknesses raise safety, cost, and sustainability concerns—issues 3D-SLISE aims to address.

A Safer, More Sustainable Battery Core

At the heart of the innovation is the replacement of conventional liquid electrolytes with a quasi-solid, slime-like material. Traditional electrolytes allow lithium ions to move between the battery’s electrodes but are highly flammable, making them a fire risk under high stress or damage.

3D-SLISE, developed under the leadership of Specially Appointed Professor Yosuke Shiratori and Associate Professor Shintaro Yasui, eliminates this risk by using a water-based borate matrix. The base composition includes amorphous lithium tetraborate, lithium salt, and carboxymethyl cellulose. This mix creates a soft, viscous interface that allows lithium ions to move freely in three dimensions, improving both conductivity and stability.

The electrolyte’s ionic conductivity reaches 2.5 milli-siemens per centimeter, a strong result for a quasi-solid system. Its activation energy of just 0.25 electron volts allows efficient ion transfer at room temperature, removing the need for special heating or cooling during operation.

Simplified Manufacturing Without High-Cost Controls

Conventional lithium-ion battery production requires expensive dry rooms and glove boxes to keep out moisture, along with high-temperature treatments to stabilize the components. These steps consume significant energy and resources.

With 3D-SLISE, none of that is necessary. The slurry can be processed and dried naturally at room temperature, reducing both production costs and the carbon footprint. This manufacturing flexibility makes the technology well-suited for large-scale industrial adoption.

The team created two slurry types:

• Type E for electrodes, combining the electrolyte with lithium cobalt oxide for the cathode and lithium titanate for the anode.

• Type S for the quasi-solid electrolyte layer, placed between the electrodes.

When assembled, these components formed a 2.35-volt battery capable of charging or discharging in just 20 minutes. The cells maintained strong performance for more than 400 cycles at ambient conditions, demonstrating durability alongside speed.

Unlocking Easier, Cleaner Recycling

One of the most striking advantages of 3D-SLISE lies in end-of-life recovery. Standard batteries are difficult to recycle because their binders and electrolytes require toxic solvents or high temperatures to separate valuable materials. The process is expensive and often incomplete, leading to significant waste.

3D-SLISE removes this barrier entirely. Because it contains no polyvinylidene di-fluoride binders or harmful solvents, the active materials can be recovered simply by soaking the electrodes in water. Metals such as cobalt can be reclaimed directly, without the need for aggressive chemical treatments.

“Using this technology, it is possible to directly reclaim valuable elements like cobalt, contributing to a stable and reliable supply of critical battery materials,” Yasui explained.

This simplicity could change how the industry approaches battery recycling. By lowering costs and eliminating hazardous steps, recycling becomes more accessible and economically viable, supporting a circular battery economy where materials are reused instead of discarded.

Meeting the Rising Demand for Energy Storage

Global demand for lithium-ion batteries is growing rapidly, driven by the shift toward electric vehicles and renewable energy storage. This growth brings increasing pressure on supply chains for lithium, cobalt, and other materials, as well as mounting environmental concerns over battery waste.

3D-SLISE’s recyclability addresses both challenges. By making recovery straightforward and inexpensive, it reduces dependence on newly mined materials and cuts waste generation. In addition, the water-based composition avoids the toxic byproducts associated with current recycling methods.

From a performance standpoint, the electrolyte’s fast-charging capability could help accelerate the adoption of electric vehicles and other battery-powered systems. Charging in 20 minutes rather than hours not only improves user convenience but also allows more efficient use of charging infrastructure.

Broad Potential Applications

While the team has so far demonstrated the technology in small-scale batteries, the approach could be adapted to a wide range of devices. Portable electronics could benefit from the improved safety and recyclability, while stationary energy storage systems could take advantage of the simpler, lower-cost production methods.

With further optimization, 3D-SLISE could even be integrated into electric vehicle batteries, where its safety profile and recycling benefits would be particularly valuable. The combination of rapid charging, long cycle life, and non-flammable chemistry could reduce fire risks and extend battery service life.

Challenges Ahead

Although promising, the technology still needs to undergo large-scale testing and optimization. Scaling up from laboratory prototypes to industrial production will require adjustments to ensure consistent quality and compatibility with existing manufacturing lines.

Energy density is another consideration. While the reported 2.35 volts is suitable for testing, electric vehicle and high-performance applications may require higher voltages. Adapting the chemistry for greater output while retaining the safety and recyclability advantages will be a key research focus.

A Step Toward Circular, Safer Batteries

The 3D-SLISE project reflects a broader shift in battery research toward designs that integrate performance, safety, and sustainability from the outset. Instead of treating recycling as an afterthought, the technology incorporates it into the battery’s core chemistry.

By simplifying manufacturing and end-of-life recovery, it offers a model for cleaner energy storage solutions that align with global sustainability goals. The reduced reliance on toxic materials and the elimination of high-energy production steps further strengthen its environmental credentials.

Outlook

If successfully commercialized, 3D-SLISE could help address three of the biggest problems in lithium-ion battery technology: flammability, costly production, and inefficient recycling. It could allow safer devices, lower manufacturing costs, and a genuine circular economy for critical battery materials.

As Professor Shiratori and Associate Professor Yasui’s team continue development, the technology stands as a reminder that advances in materials science can have ripple effects across multiple sectors. From consumer electronics to electric vehicles, safer and more sustainable batteries could be within reach—thanks, in this case, to a slime-like substance that rewrites the rules of energy storage.