A team of engineers led by 94-year-old John Goodenough, professor within the Cockrell School of Engineering on the University of Texas at Austin and co-inventor from the lithium battery pack, has evolved the initial all-solid-state battery cells that may lead to safer, faster-charging, longer-lasting rechargeable batteries for handheld mobile devices, electric cars and stationary energy storage.
Goodenough’s latest breakthrough, completed with Cockrell School senior research fellow Maria Helena Braga, is a low-cost all-solid-state battery that is certainly noncombustible and has a lengthy cycle life (battery life) by using a high volumetric energy density and fast rates of charge and discharge. The engineers describe their new technology within a recent paper published within the journal Energy & Environmental Science.
“Cost, safety, energy density, rates of charge and discharge and cycle life are critical for battery-driven cars to get more widely adopted. We feel our discovery solves a lot of the problems that are built into today’s batteries,” Goodenough said.
The researchers demonstrated that the new battery cells have at the very least three times just as much energy density as today’s lithium-ion batteries. A battery cell’s energy density gives an electric vehicle its driving range, so a greater energy density ensures that a car can drive more miles between charges. The UT Austin battery formulation also provides for a larger variety of charging and discharging cycles, which equates to longer-lasting batteries, as well as a faster rate of recharge (minutes rather than hours).
Today’s lithium-ion batteries use liquid electrolytes to transport the lithium ions between the anode (the negative side from the battery) and the cathode (the positive side of the battery). If lithium battery storage is charged too rapidly, it can cause dendrites or “metal whiskers” to form and cross through the liquid electrolytes, resulting in a short circuit that can result in explosions and fires. As opposed to liquid electrolytes, they rely on glass electrolytes which allow using an alkali-metal anode with no formation of dendrites.
Using an alkali-metal anode (lithium, sodium or potassium) – which isn’t possible with conventional batteries – increases the energy density of any cathode and delivers a long cycle life. In experiments, the researchers’ cells have demonstrated greater than 1,200 cycles with low cell resistance.
Additionally, as the solid-glass electrolytes can operate, or have high conductivity, at -20 degrees Celsius, this kind of battery in a vehicle could work well in subzero degree weather. This dexkpky82 the first all-solid-state battery cell that could operate under 60 degree Celsius.
Braga began developing solid-glass electrolytes with colleagues while she was in the University of Porto in Portugal. About two years ago, she began collaborating with Goodenough and researcher Andrew J. Murchison at UT Austin. Braga mentioned that Goodenough brought a preliminary understanding from the composition and properties from the solid-glass electrolytes that contributed to a whole new version of your electrolytes that may be now patented from the UT Austin Office of Technology Commercialization.
The engineers’ glass electrolytes let them plate and strip alkali metals for both the cathode and the anode side without dendrites, which simplifies battery cell fabrication.
An additional benefit would be that the battery cells can be produced from earth-friendly materials.
“The glass electrolytes enable the substitution of low-cost sodium for lithium. Sodium is extracted from seawater that may be widely available,” Braga said.
Goodenough and Braga are continuing to advance their 26650 battery pack and therefore are working on several patents. For the short term, they hope to use battery makers to build up and test their new materials in electric vehicles and energy storage devices.