Solid State Battery Promises Faster Charging, Longer Life and Increased Safety

The solid state battery will be charged for some time, running the cooler and packing energy into less space than traditional lithium-ion versions.

A new UC Riverside review published in NanoEnergy explains why the technology is poised to change everything from electric vehicles to home appliances, representing major leap in energy storage.

These batteries replace the flammable liquids found in standard versions with a safer and much more efficient solid material. If today’s battery can take 30-45 minutes to reach 80% charge, the solid-state model can reduce that time to 12 minutes.

The lead author of UCR’s Mechanical Engineering professor Cengiz Ozkan said the benefits depend on chemistry and engineering. “By removing the liquid and using a stable solid material instead, more power can be safely pushed into the battery at once without the risk of overheating or fire,” he said.

Traditional lithium-ion batteries move lithium ions, the particles that carry charge, through liquids. However, the liquid can deteriorate over time, limiting the charging speed and pose a risk of fire. Solid-state batteries use solid-state materials instead. This provides a safer and more stable environment for lithium ions to migrate. This allows for faster and more efficient charging with fewer safety concerns.

The solids in these batteries are known as solid electrolytes. This review highlights three main types: sulfide-based, oxide-based and polymer-based. Each type has its strengths. Some allow ions to travel faster, while others provide better long-term stability or easier to manufacture. One outstanding group, sulfide-based electrolytes, work almost like liquids in current batteries, but with no drawbacks.

Researchers also explain the tools scientists are using to watch the tools they are currently using in real time. Techniques such as neutron imaging and powerful X-rays allow researchers to see how lithium moves within the battery in response to charging and discharging. This helps identify areas that are packed with lithium, or areas where unnecessary structures called “dendrites” begin to grow. A dendrite is a small needle-like layer that can short or break down the battery.

Understanding these internal tasks is key to creating a better battery. “These imaging tools are like MRIs on batteries,” Ozkan said. “They can look at the vital signs on the battery and make smarter design choices.”

Solid-state batteries tend to use lithium more efficiently. Many designs feature a lithium metal layer that can store energy in less space than the graphite layer used in today’s batteries. This means that the solid-state battery is lighter and smaller, and that the device has been powered up for a long time, or even longer.

Typically, traditional lithium-ion batteries begin to show significant decomposition after about 5-8 years of use in electric vehicles, but depending on usage and environmental factors, solid-state batteries can continue to function for more than 15-20 years.

“As electric vehicles, renewable energy grids, portable electronics and aerospace systems become more broad and demanding, traditional lithium-ion batteries are reaching performance and safety limits,” Ozkan said.

Ozkan said solid-state batteries could also play a pivotal role in the future of interstellar travel and space exploration.

Due to their thermal stability, these batteries are more suitable to withstand extreme temperatures and radiation conditions in space. It also stores more power in less space. This is important for missions where all cubic centimeters are counted. Also, without liquid electrolytes, it is more reliable in closed oxygen-controlled environments such as spacecraft and planetary bases.

The researchers’ goal for this review was to guide researchers and engineers to accelerate the development, scalability, and practical deployment of solid-state systems.

However, the challenges remain. Manufacturing these batteries on a large scale remains difficult and expensive. This paper provides a roadmap for solving these problems. These include developing better materials, refinement of interactions between battery parts, and improving factory technology to facilitate production.

“Solid-state batteries are getting closer to reality every day,” Ozkan said. “Our reviews show how far science has come, and what steps are needed to follow to make these batteries available for daily use.”