Samsung’s exploding Galaxy Note 7 smartphone may have been the most infamous example, but plenty of devices which rely on lithium-ion batteries have had their share of combustible incidents. While statistically rare, this is one of the risks of lithium-ion technology; frequently caused by problems with the permeable polyethylene separator that keeps the battery’s cathode and anode components separate.
A new piece of research coming out of the University of Michigan could help make for safer, less combustible batteries, however — and it may do so while doubling the output of current lithium-ion cells, and without taking up any more space.
“We have developed and demonstrated an effective approach to enable a new battery technology that uses a solid ceramic electrolyte instead of a liquid,” Jeff Sakamoto, an associate professor of Mechanical Engineering at the University of Michigan, told Digital Trends. “This ceramic is unique owing to its stability against lithium metal and high conductivity at room temperature. These two attributes enable the use of metallic lithium anodes, which could double the energy density compared to lithium-ion technology. Historically, lithium-ion performance has increased by a few percent per year over the last two decades. Moreover, lithium-ion performance is cresting at about 600 watt-hours per liter. This battery would enable a 100 percent improvement in energy density.”
In tests, the ceramic electrolyte has shown no visible degradation after long-term cycling, a problem which can eventually kill regular lithium-ion batteries. The technology could also lead to significantly faster charging times.
But could it really do away with the risk of exploding batteries altogether? While it may make a “dramatic” difference, Sakamoto acknowledged that more research needs to be done. “Our ceramic electrolyte is made at 1,000[-degrees] Celsius in air,” he continued. “It is not combustible. However, lithium metal is also reactive, but not flammable. We are conducting tests to quantify the safety of lithium metal-based batteries, and acknowledge that lithium metal may pose safety risks, too.”
The next phase of research involves developing a manufacturing process. It is hoped that this can be demonstrated a little under one year from now, by July 2019. “We hope to have a pre-pilot scale process in place by then,” Sakamoto said. “There are still many challenges, but we are making progress and learning a lot along the way.”
A paper describing the work was recently published in the Journal of Power Sources.