A team of engineers led by 94-year-old John Goodenough, professor within the Cockrell School of Engineering at The University of Texas at Austin and co-inventor of the custom lithium battery, has continued to evolve the initial all-solid-state battery cells that could lead to safer, faster-charging, longer-lasting rechargeable batteries for handheld smart phones, 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 noncombustible and possesses an extensive cycle life (life of the battery) by using a high volumetric energy density and fast rates of charge and discharge. The engineers describe their new technology in a recent paper published within the journal Energy & Environmental Science.
“Cost, safety, energy density, rates of charge and discharge and cycle life are crucial for battery-driven cars being more widely adopted. We know our discovery solves a lot of the conditions that are built into today’s batteries,” Goodenough said.
The researchers demonstrated that the new battery cells have a minimum of three times just as much energy density as today’s lithium-ion batteries. A battery cell’s energy density gives an electric powered vehicle its driving range, so a higher energy density ensures that an auto can drive more miles between charges. The UT Austin battery formulation also enables an increased number of charging and discharging cycles, which equates to longer-lasting batteries, in addition to a faster rate of recharge (minutes instead of 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 your battery). If energy storage companies is charged too quickly, it may cause dendrites or “metal whiskers” to produce and cross with the liquid electrolytes, creating a short circuit that can result in explosions and fires. Rather than liquid electrolytes, they depend on glass electrolytes which allow using an alkali-metal anode with no formation of dendrites.
The application of an alkali-metal anode (lithium, sodium or potassium) – which isn’t possible with conventional batteries – improves the energy density of any cathode and delivers a long cycle life. In experiments, the researchers’ cells have demonstrated over 1,200 cycles with low cell resistance.
Additionally, because the solid-glass electrolytes can operate, or have high conductivity, at -20 degrees Celsius, this kind of battery in the vehicle could perform well in subzero degree weather. This dexkpky82 the 1st all-solid-state battery cell that may operate under 60 degree Celsius.
Braga began developing solid-glass electrolytes with colleagues while she was at the University of Porto in Portugal. About two years ago, she began collaborating with Goodenough and researcher Andrew J. Murchison at UT Austin. Braga said that Goodenough brought an awareness from the composition and properties in the solid-glass electrolytes that ended in a brand new version of your electrolytes that is now patented through the UT Austin Office of Technology Commercialization.
The engineers’ glass electrolytes permit them to plate and strip alkali metals on the cathode as well as the anode side without dendrites, which simplifies battery cell fabrication.
An additional benefit is the fact that battery cells can be created from earth-friendly materials.
“The glass electrolytes permit the substitution of low-cost sodium for lithium. Sodium is extracted from seawater that is widely accessible,” Braga said.
Goodenough and Braga are continuing to succeed their 18500 battery and they are concentrating on several patents. For the short term, they hope to use battery makers to develop and test their new materials in electric vehicles and energy storage devices.