Critics may struggle to stifle a yawn, as battery ‘breakthroughs’ are regularly promised or hinted at, but the actual pace of change in EV battery tech seems quite slow. On the other hand, solid-state batteries may be the best way forward if tests can be successfully turned into full-scale production. The original report headline says: ‘VW and Bill Gates-backed QuantumScape releases performance data…’, so plenty of industrial and financial muscle behind the project.
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California-based QuantumScape Corp (QuantumScape), a company focussing on the development of next-generation solid-state lithium-metal batteries for use in electric vehicles (EVs), has released performance data, which it says demonstrates its capability to address fundamental issues holding back widespread adoption of high-energy-density solid-state batteries, including charge time (current density), cycle life, safety, and operating temperature. Autocar Pro reporting.
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The company says a commercially viable solid-state lithium-metal battery is an advancement that the battery industry has pursued for decades, as it holds the promise of a step function increase in energy density over conventional lithium-ion batteries, enabling electric vehicles with a driving range comparable to combustion engine-based vehicles.
QuantumScape claims its solid-state battery is designed to enable up to 80 percent longer range compared to today’s lithium-ion batteries.
Previous attempts to create a solid-state separator capable of working with lithium metal at high rates of power generally required compromising other aspects of the cell (cycle life, operating temperature, safety, cathode loading, or excess lithium in the anode).
QuantumScape says its newly-released results, based on testing of single layer battery cells, show its solid-state separators are capable of working at very high rates of power, enabling a 15-minute charge to 80% capacity, faster than either conventional battery or alternative solid-state approaches are capable of delivering.
In addition, the data points out that the new battery technology is capable of lasting hundreds of thousands of miles, and is designed to operate at a wide range of temperatures, including results that show operation at -30 degrees Celsius.
The company says the tested cells were large-area single-layer pouch cells in the target commercial form factor with zero excess lithium on the anode and thick cathodes (>3mAh/cm2), running at rates of one-hour charge and discharge (1C charge and 1C discharge) at 30 degrees Celsius.
These tests demonstrated robust performance of these single layer pouch cells even at these high rates, resulting in retained capacity of greater than 80 percent after 800 cycles (demonstrating high columbic efficiency of greater than 99.97%).
Dr. Stanley Whittingham, co-inventor of lithium-ion battery and winner of the 2019 Nobel Prize in Chemistry said: “The hardest part about making a working solid-state battery is the need to simultaneously meet the requirements of high energy density (1,000 Wh/L), fast charge (i.e., high current density), long cycle life (greater than 800 cycles), and wide temperature-range operation. This data shows QuantumScape’s cells meet all of these requirements, something that has never before been reported. If QuantumScape can get this technology into mass production, it holds the potential to transform the industry.”
Venkat Viswanathan, battery expert and professor of materials science at Carnegie-Mellon University said: “These results blow away what was previously thought to be possible in a solid-state battery. Supporting high enough current density to enable fast charge without forming dendrites has long been a holy grail of the industry. This data shows the capability to charge to 80% capacity in 15 minutes, corresponding to an astonishingly high rate of lithium deposition of up to a micron per minute.”
The company says its team of scientists have worked over the past decade to create the next generation of battery technology: solid-state batteries with lithium-metal anodes.
via Tallbloke’s Talkshop
December 10, 2020 at 11:33AM