From left:
1) The all solid-state battery consists of a cathode composite layer, a sulfide solid electrolyte layer, and a carbon free micro-silicon anode.
2) Before charging, discrete micro-scale Silicon particles make up the energy dense anode. During battery charging, positive Lithium ions move from the cathode to the anode, and a stable 2D interface is formed.
3) As more Lithium ions move into the anode, it reacts with micro-Silicon to form interconnected Lithium-Silicon alloy (Li-Si) particles. The reaction continues to propagate throughout the electrode.
4) The reaction causes expansion and densification of the micro-Silicon particles, forming a dense Li-Si alloy electrode. The mechanical properties of the Li-Si alloy and the solid electrolyte have a crucial role in maintaining the integrity and contact along the 2D interfacial plane.
Engineers create a high performance all-solid-state battery with a pure-silicon anode
Engineers created a new type of battery that weaves two promising battery sub-fields into a single battery. The battery uses both a solid state electrolyte and an all-silicon anode, making it a silicon all-solid-state battery. The initial rounds of tests show that the new battery is safe, long lasting, and energy dense. It holds promise for a wide range of applications from grid storage to electric vehicles.
The battery technology is described in the Sept. 24, 2021 issue of the journal Science. University of California San Diego nanoengineers led the research, in collaboration with researchers at LG Energy Solution.

Silicon anodes are famous for their energy density, which is 10 times greater than the graphite anodes most often used in today’s commercial lithium ion batteries. On the other hand, silicon anodes are infamous for how they expand and contract as the battery charges and discharges, and for how they degrade with liquid electrolytes. These challenges have kept all-silicon anodes out of commercial lithium ion batteries despite the tantalizing energy density. The new work published in Science provides a promising path forward for all-silicon-anodes, thanks to the right electrolyte.
“With this battery configuration, we are opening a new territory for solid-state batteries using alloy anodes such as silicon,” said Darren H. S. Tan, the lead author on the paper. He recently completed his chemical engineering PhD at the UC San Diego Jacobs School of Engineering and co-founded a startup UNIGRID Battery that has licensed this technology.
Next-generation, solid-state batteries with high energy densities have always relied on metallic lithium as an anode. But that places restrictions on battery charge rates and the need for elevated temperature (usually 60 degrees Celsius or higher) during charging. The silicon anode overcomes these limitations, allowing much faster charge rates at room to low temperatures, while maintaining high energy densities.
The team demonstrated a laboratory scale full cell that delivers 500 charge and discharge cycles with 80% capacity retention at room temperature, which represents exciting progress for both the silicon anode and solid state battery communities.
Silicon as an anode to replace graphite
Silicon anodes, of course, are not new. For decades, scientists and battery manufacturers have looked to silicon as an energy-dense material to mix into, or completely replace, conventional graphite anodes in lithium-ion batteries. Theoretically, silicon offers approximately 10 times the storage capacity of graphite. In practice however, lithium-ion batteries with silicon added to the anode to increase energy density typically suffer from real-world performance issues: in particular, the number of times the battery can be charged and discharged while maintaining performance is not high enough.
Much of the problem is caused by the interaction between silicon anodes and the liquid electrolytes they have been paired with. The situation is complicated by large volume expansion of silicon particles during charge and discharge. This results in severe capacity losses over time.
“As battery researchers, it’s vital to address the root problems in the system. For silicon anodes, we know that one of the big issues is the liquid electrolyte interface instability,” said UC San Diego nanoengineering professor Shirley Meng, the corresponding author on the Science paper, and director of the Institute for Materials Discovery and Design at UC San Diego. “We needed a totally different approach,” said Meng.
Indeed, the UC San Diego led team took a different approach: they eliminated the carbon and the binders that went with all-silicon anodes. In addition, the researchers used micro-silicon, which is less processed and less expensive than nano-silicon that is more often used.
An all solid-state solution
In addition to removing all carbon and binders from the anode, the team also removed the liquid electrolyte. Instead, they used a sulfide-based solid electrolyte. Their experiments showed this solid electrolyte is extremely stable in batteries with all-silicon anodes.
“This new work offers a promising solution to the silicon anode problem, though there is more work to do,” said professor Meng, “I see this project as a validation of our approach to battery research here at UC San Diego. We pair the most rigorous theoretical and experimental work with creativity and outside-the-box thinking. We also know how to interact with industry partners while pursuing tough fundamental challenges.”
Past efforts to commercialize silicon alloy anodes mainly focus on silicon-graphite composites, or on combining nano-structured particles with polymeric binders. But they still struggle with poor stability.
By swapping out the liquid electrolyte for a solid electrolyte, and at the same time removing the carbon and binders from the silicon anode, the researchers avoided a series of related challenges that arise when anodes become soaked in the organic liquid electrolyte as the battery functions.
At the same time, by eliminating the carbon in the anode, the team significantly reduced the interfacial contact (and unwanted side reactions) with the solid electrolyte, avoiding continuous capacity loss that typically occurs with liquid-based electrolytes.
This two-part move allowed the researchers to fully reap the benefits of low cost, high energy and environmentally benign properties of silicon.
Impact & Spin-off Commercialization
“The solid-state silicon approach overcomes many limitations in conventional batteries. It presents exciting opportunities for us to meet market demands for higher volumetric energy, lowered costs, and safer batteries especially for grid energy storage,” said Darren H. S. Tan, the first author on the Science paper.
Sulfide-based solid electrolytes were often believed to be highly unstable. However, this was based on traditional thermodynamic interpretations used in liquid electrolyte systems, which did not account for the excellent kinetic stability of solid electrolytes. The team saw an opportunity to utilize this counterintuitive property to create a highly stable anode.
Tan is the CEO and cofounder of a startup, UNIGRID Battery, that has licensed the technology for these silicon all solid-state batteries.
Original Article: A New Solid-state Battery Surprises the Researchers Who Created It
More from: University of California San Diego
The Latest Updates from Bing News & Google News
Go deeper with Bing News on:
All-solid-state battery
- Quantumscape Q2 2022 report: 24-layer solid-state cells, scaled manufacturing, and two new OEM customerson August 1, 2022 at 10:07 am
Solid-state battery manufacturer Quantumscape has released its second quarterly report for 2022, updating the public to its progress in scaling affordable, energy dense cells for future EVs. The ...
- Study: solid state batteries can further boost climate benefits of EVson July 23, 2022 at 11:43 pm
Solid state batteries can reduce the carbon footprint of electric vehicle batteries by almost two-fifths – further increasing EVs’ advantage over fossil fuel vehicles. That’s according to research ...
- What Is a Solid State Battery For an EV? How Do They Work?on July 22, 2022 at 3:30 am
EVs are slowly taking over the automotive market worldwide. There was a time when skepticism abounded regarding when EV adoption would actually take off, but now EVs are selling so well that ...
- Solid state tech could reduce EV batteries' carbon footprint by 39%, research suggestson July 20, 2022 at 8:00 am
Solid-state batteries achieved an overall reduction of 24% based on the technology alone, and 39% with sustainable materials, according to a company that does lifecycle analysis.
- Solid-state tech can reduce EV batteries’ CO2 emissions by nearly 40%on July 20, 2022 at 5:42 am
However, new research by Minviro, a company specialized in raw material life-cycle analysis, has found that an emerging battery technology can significantly reduce an EV’s carbon footprint: ...
Go deeper with Google Headlines on:
All-solid-state battery
Go deeper with Bing News on:
Silicon all-solid-state battery
- Nio confirms plans to release 150 kWh battery in 2022on July 28, 2022 at 3:35 pm
The Chinese electric carmaker has confirmed its earlier timetables, according to which the first vehicles with the 150 kWh solid-state battery will be delivered this year. There will also be flexible ...
- Global Silicon Carbide Power Electronics Market Report 2022: Next Generation Automation of EVs and Home and Campus Electricity storageon July 25, 2022 at 3:18 am
Dublin, July 25, 2022 (GLOBE NEWSWIRE) -- The "Silicon Carbide Power Electronics: Market Shares, Market Forecasts, Market Analysis, 2022-2028" report from Wintergreen Research, Inc has been added ...
- Global Silicon Carbide Power Electronics Market to 2028: Market Growth is the Result of Rapid Adoption of EV Electric Vehicleson July 22, 2022 at 5:17 am
Silicon Carbide represents next generation automation of EVs and home and campus electricity storage, a market in line for significant growth. The electrical solid state battery energy industry ...
- Solid-state tech can reduce EV batteries’ CO2 emissions by nearly 40%on July 20, 2022 at 5:42 am
However, new research by Minviro, a company specialized in raw material life-cycle analysis, has found that an emerging battery technology can significantly reduce an EV’s carbon footprint: ...
- EV Solid-State Battery Deployment To Get Delayed By 2030: Reporton July 18, 2022 at 3:06 am
the solid structure and fused components in solid-state battery cells are susceptible to delamination when using a silicon anode and pose a challenge to recycling. The dendrite issue doesn't go ...