Engineers, researchers and others are increasingly interested in power source developments as electric vehicles become more widely adopted. Much of their work centers on solid-state batteries, which use solid electrolytes rather than gels or liquids for ionic conductions between electrodes. This option holds much potential for improving EV range and making these cars more appealing to consumers.

What have researchers accomplished, and what can people interested in this subject expect for the future?

Pinpointing the Mechanisms That Cause Failures

Research into solid-state batteries with lithium metal anodes suggests these options could increase EVs’ performance while giving them longer ranges and making them safer. A team recently overcame known technical limitations, moving these possibilities closer to widespread use. They used advanced imaging techniques to learn more about an issue that creates the potential for these batteries to short-circuit.

The problem occurs when lithium metal filaments crack through the battery’s ceramic electrolyte. These researchers used X-ray computed tomography to verify that the cracks’ initiation and propagation happen separately.

Additionally, the openings form when lithium builds up in subsurface pores. Once they become full, charging the battery increases the pressure, causing the cracks. Conversely, propagation can happen before the pores fill, driven by a wedge-shaped mechanism that spreads the cracks from the rear.

Those involved with this project believe the findings can help them address some of the shortcomings that have restricted lithium metal solid-state batteries so far. For example, this study’s results confirmed that while pressure can prevent the formation of interface gaps, it can also make cracks form once it is too high.

Such findings can help battery manufacturers develop practical strategies to mitigate these structural failures. The associated progress would support EV advancements, along with potential applications in aircraft and consumer electronics.

Accelerating Mass-Production Options for Sodium Batteries

As academics and battery industry professionals explore solid-state batteries, many hope sodium-based options will ease supply chain difficulties because the raw materials would be easier to source than lithium. One effort came when researchers focused on using sodium polysulfides containing at least two sulfur atoms as both the primary material and flux.

This approach allowed them to produce a solid sulfide electrolyte with the highest known sodium ion conductivity. Tests showed the electrolyte was about 10 times more conductive than practical applications would require. The team also made a glass electrolyte characterized by high reduction resistance.

The group’s lab-based work suggested their processes could enable the mass synthesis of electrolytes that offer high conductivity and excellent formability. This would make creating solid-state batteries for various potential applications easier. Additionally, they determined that their developed process facilitates conveniently obtaining high-performance materials, which could bring improved batteries into the mainstream.

Achieving a Sodium Battery Breakthrough

Consumers mention various factors that may discourage them from driving electric vehicles. Many of their worries relate to range and charging times. Most drivers are well-accustomed to having little or no difficulty finding gas stations when needed. However, depending on the charger used, it can take up to 20 hours to replenish EVs’ power sources. That explains why researchers and electric car owners are so eager to find more efficient options.

One group made significant progress by creating a battery with the energy density of lithium. This innovation was the first anode-free, solid-state power source made from sodium. Those working on this project believe it will make batteries more affordable and eco-friendly than conventional options. They could also charge quickly, making them especially appealing to people interested in buying EVs but don’t want to experience battery-related inconveniences.

The researchers also made a design change that deviated from the usual way of making anode-free batteries. These power sources typically have an electrolyte around the current collector. However, this team made the current collector surround the electrolyte. They believed the swap would prevent a solid electrolyte interphase buildup, which consumes active materials and makes the battery less useful over time.

Assessing Aluminum as a Lithium Replacement

Most people who develop solid-state batteries understand the need to pursue future-oriented options that account for known challenges. A case in point is the growing evidence suggesting lithium shortages could become problematic sooner than industry professionals realize. Additionally, geopolitical tension and price fluctuations increase supply chain instability, leaving manufacturers who rely on lithium batteries spending more time finding the in-demand resource.

In one promising example, researchers are exploring whether aluminum could become a viable material for solid-state batteries. They developed an aluminum foil-based system that could result in EVs running longer per charge and their batteries becoming more affordable to manufacture.

The group was already aware of the possibility of using aluminum as an anode material. However, they failed too rapidly when testing pure aluminum foils in that application. The researchers dealt with that challenge by testing more than 100 materials to add in small amounts, creating microstructured foils that showed significantly improved performance and stability when used in solid-state power sources.

Additionally, experiments showed that the aluminum anodes stored more lithium than conventional ones and were cost-effective to produce. The latter benefit was partially because the researchers’ method eliminated many of the manufacturing steps for traditional anodes.

Besides changing how well electric vehicle batteries work, the researchers said this progress could also improve short-range electric aircraft capabilities. It could allow planes to fly further than the current maximum distance of about 150 miles.

Substantial Momentum for Solid-State Batteries

Numerous obstacles and limitations have stopped solid-state batteries from reaching the mainstream, even as people learn more about their advantages over current options. However, innovations will encourage EV industry professionals to keep investigating and investing in the solid-state technologies that seem most viable for current and future business needs.

Not all attempts lead to mainstream successes, but even those that fall short of expectations will contain valuable information to shape how other projects proceed. Additionally, the more frequently researchers can prove that solid-state batteries are worth attention, the easier it will be to get funding, investor attention and other resources that make experimental work more viable in real-world applications.