Solid silicon battery: Cheaper e-cars and more range

Researchers of the University of San Diego shared with LG Energy one Discovery made , resulting in two very promising types of battery technologies let combine. They developed a solid battery with a silicon anode .

Solid-state batteries are considered to be trend-setting for electromobility, because they have a higher efficiency, much greater range, better Safety, a longer lifespan and significantly faster charging speeds.

According to the UC San Diego, the first tests show that the new battery is safe and durable. They promise a wide range of applications from network storage systems to electric vehicles.

The problem and the solution

Silicon is theoretically an optimal material for the anode, since it increases the capacity by the Factor 10 to conventional graphite anodes. The problem is that silicon anodes tend to expand and contract quickly as a battery is charged and discharged, and the battery capacity decreases quickly. Especially with the liquid electrolytes currently used in lithium-ion cells. That is why silicon anodes have not been used until now.

Solid-state batteries with high energy densities have always relied on metallic lithium as an anode. However, this also has disadvantages – so it has to be charged to about 60 degrees Celsius are heated. An energy expenditure that should not be underestimated, especially in winter.

The work of the scientists now has a solution for both of these disadvantages. This is made possible by the fact that they eliminate the carbon and binders that were used in pure silicon anodes. In addition, they use the cheaper nanosilicon instead of the commonly used microsilicon. There is also a solid electrolyte based on sulfide for use.

Problems avoided

The researchers avoided this a series of problems that arise when the anodes are saturated with the organic liquid electrolyte while the battery is in operation, according to the press release.

At the same time, the team was able to due to the elimination of the carbon in the anode undesirable side reactions significantly reduce with the solid electrolyte and thus avoid the continuous loss of capacity that normally occurs with liquid-based electrolytes.

Promising tests

The changes showed that Vollsil silicon anodes in the solid electrolyte were much more stable and after 500 charge and discharge cycles in the laboratory at room temperature 80 percent of capacity retained. They could also be charged faster than previous silicon anode batteries.

“The solid-state silicon approach overcomes many of the limitations of conventional batteries. lower costs and safer batteries, especially for energy storage in the network, “said Darren HS Tan , the senior author of the scientific paper.

The technology was already to a company named Unigrid Battery licensed, and LG Energy Storage plans to expand the research. Everything is currently still in the development stage and it is unclear whether the batteries work as well in practice as they do in reality.

The researcher’s paper is in Science appeared.