Energy

New all-solid-state battery holds promise for grid storage and EVs

Next-generation battery technology could be unlocked by a combination of solid-state electrolytes and a dash of silicon, new research shows
Next-generation battery technology could be unlocked by a combination of solid-state electrolytes and a dash of silicon, new research shows

Two highly promising pathways in the pursuit of next-gen battery technology involve using solid-state electrolytes rather than liquid ones, and adding silicon to the anode component to boost energy density. A newly developed architecture places these two innovations within one device to form a solid-state battery that is safe, long-lasting and has the potential to store vast amounts of energy.

For many years, scientists have been allured by the game-changing energy density silicon promises next-generation batteries, but bringing it into the mix has its challenges. The idea is to incorporate or entirely replace the graphite used as the anode with silicon to potentially store as much as 10 times the lithium ions. The trouble is silicon causes the liquid electrolyte to quickly degrade and the battery to quickly fail, but the authors of this new study believe the solution may lie in using a solid-state electrolyte instead.

Like silicon anodes, solid-state electrolytes are another branch of battery research that could open up some exciting possibilities. The conventional liquid electrolyte that carries the lithium ions back and forth between the anode and a battery's other electrode, the cathode, is highly volatile, which limits compatibility with other prospective, high-performance materials such as lithium metal. Solid-state electrolytes shape as a promising solution to this problem.

Engineers at the University of California, San Diego suspected a solid-sate electrolyte might bring some similar advantages to silicon anodes. Efforts to incorporate silicon into the anodes of lithium batteries have been plagued by fluctuations in the size of the silicon particles, which expand and contract as the device charges and discharges. This combines with unstable interactions between the silicon anode and liquid electrolyte to drive severe capacity losses as the battery is cycled.

“As battery researchers, it’s vital to address the root problems in the system," says Shirley Meng, the corresponding author. "For silicon anodes, we know that one of the big issues is the liquid electrolyte interface instability. We needed a totally different approach."

This new approach involved making some tweaks to the way the silicon anode is put together, with the scientists eliminating carbon and binders that are normally used, and opting for a cheaper form of micro-silicon that undergoes less processing. A sulfide-based solid electrolyte was then introduced to carry the charge, and the resulting battery proved extremely stable, by avoiding the damaging interactions at the anode.

The novel silicon all-solid-state battery is described as safe, long-lasting and energy dense. A lab-scale full cell was shown to be capable of 500 charge and discharge cycles while retaining 80 percent of its capacity, demonstrating the stabilizing effects of the new design.

“The solid-state silicon approach overcomes many limitations in conventional batteries," says Darren H. S. Tan, first author and CEO of startup UNGRID Battery, which has licensed the technology. "It presents exciting opportunities for us to meet market demands for higher volumetric energy, lowered costs, and safer batteries especially for grid energy storage."

The research was published in the journal Science, while the video below provides an overview of the breakthrough.

Source: UC San Diego

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5 comments
EricVerhulst
500 cycles for 80% energy left, is not a lot. Sustainability requires 10 to 20 years lifetime. Hybrid powercapacitors, 80 to 230 Wh/Kg and upto 20000 cycles, upto 20C charging and in production. See this article from March 2020: https://newatlas.com/energy/toomen-powercapacitors-kurt-energy-high-density-supercapacitors/.
Bob Stuart
If they are not bragging about the efficiency and charge times, they must be problems.
michael39
Solid State batteries are a long way off. A few players claim that they have usable prototypes. TOYOTA recently announced a prototype, running and using some sort of solid state battery. These are still years or decades from practical production. Lets see Charge Times, Cyclic durability and energy density numbers.
HoppyHopkins
If they manage to obtain a ten to one hundred fold number of charge cycles and still get a ten fold increase energy and power density increase. Then all electric systems might just have a chance of being economically feasible.
WB
post 215 about some new battery tech that never sees the light of day in production ten years from now... waiting for 216...