How long the battery of your phone or computer lasts depends on how many lithium ions can be stored in the battery’s negative electrode material. If the battery runs out of these ions, it can’t generate an electrical current to run a device and ultimately fails.
Materials with a higher lithium-ion storage capacity are either too heavy or the wrong shape to replace graphite, the electrode material currently used in today’s batteries.
Purdue University scientists and engineers have introduced a potential way that these materials could be restructured into a new electrode design that would allow them to increase a battery’s lifespan, make it more stable and shorten its charging time.
The study, appearing as the cover of the September issue of Applied Nano Materials, created a net-like structure, called a “nanochain,” of antimony, a metalloid known to enhance lithium-ion charge capacity in batteries.
The researchers compared the nanochain electrodes to graphite electrodes, finding that when coin cell batteries with the nanochain electrode were only charged for 30 minutes, they achieved double the lithium-ion capacity for 100 charge-discharge cycles.
Some types of commercial batteries already use carbon-metal composites similar to antimony metal negative electrodes, but the material tends to expand up to three times as it takes in lithium ions, causing it to become a safety hazard as the battery charges.
“You want to accommodate that type of expansion in your smartphone batteries. That way you’re not carrying around something unsafe,” said Vilas Pol, a Purdue associate professor of chemical engineering.