Researchers have created a lithium-ion battery whose anode is made of sand which outperforms the industry standard by three times.
Researchers at the Bournes College of engineering at the University of California, Riverside, have developed a new lithium ion battery that outperforms the industry standard for Li-ion batteries by three times. The key ingredient to these new batteries is sand.
“This is the holy grail – a low cost, non-toxic, environmentally friendly way to produce high-performance lithium ion battery anodes” said Zachary Favors, a graduate student at the college. Favors came up with the idea months earlier while at the beach. He picked up a handful of sand and studying it, realized that it was mostly composed of quartz (SiO4), a promising new material for use in batteries.
A lithium ion battery is composed of two separated chambers. When charged, positively charged lithium ions travel from one side of the battery to the other. This creates an imbalance in the the battery; a surplus of negative charge in the anode, and a surplus of positive charge in the cathode. When the anode and cathode are connected (e.g. by connecting the battery to an electronic device), the imbalance drives electrons from the anode to the cathode, producing a current.
Function of a lithium ion battery – credit: sustainable-nano.com
Favors research has been centered on improving the anode, which in contemporary lithium ion batteries are made from graphite. Unfortunately, graphite has failed to keep up with the continual advancements in electronics, and so, alternative materials have been sought. Silicon is a contender, but it suffers from being difficult to produce and hard to stabilize.
During his research, Favors traveled to Cedar Creek Reservoir, east of Dallas, where he discovered that the sand in the beaches had a high concentration of quartz. He took a sample home, and put it through a series of purification processes which managed to refine the sand into pure silicon. During the process, the silicon formed a sponge-like structure which turned out to be key to the performance boost.
For electric vehicles, the improved battery design could lead to batteries with a three times longer lifespan. For personal electronics, battery life between charging could be increased by a similar amount.
The findings were just published in a paper, “Scalable Synthesis of Nano-Silicon from Beach Sand for Long Cycle Life Li-ion Batteries,” in the journal Nature Scientific Reports.