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IPFS News Link • Battery Project

Pre-loaded silicon anodes boost lithium battery density by 25 percent

• New Atlas

Using the plentiful element as a lithium-ion battery's anode could significantly improve its energy density, and scientists in Korea have now come up with a solution to one of the key hurdles standing in its way.

Today's lithium-ion batteries use graphite as the material for the anode, the positively-charged electrode that works with the negatively charged cathode to shuttle the lithium ions back and forth during charging. While these batteries are capable of powering today's mobile phones and electric cars, swapping the graphite for silicon, which can store four times the amount of lithium ions, could lead to phones that last for days or cars that travel hundreds of miles further on each charge.

But working silicon into a lithium-ion battery that makes the most of this potential has proven problematic. One of the issues scientists have been working to solve is the rapid decline in capacity, with silicon-based anodes shedding more than 20 percent of their lithium ions just during the initial charging cycle.

One of the ways that this could be overcome is through a technique known as "lithium pre-loading," where extra lithium is added before the battery is assembled to make up for the losses during cycling. Often this is attempted through the use of lithium powders, though this is expensive and brings safety risks.