Researchers developed cheap, strong lithium-ion battery

Researchers at USC have developed a new lithium-ion battery design that uses porous silicon nanoparticles in place of the traditional graphite anodes to provide superior performance.

The new batteries—which could be used in anything from cell phones to —hold three times as much energy as comparable graphite-based designs and recharge within 10 minutes. The design, currently under a provisional patent, could be commercially available within two to three years.

"It's an exciting research. It opens the door for the design of the next generation batteries," said Chongwu Zhou, professor at the USC Viterbi School of Engineering, who led the team that developed the battery. Zhou worked with USC graduate students Mingyuan Ge, Jipeng Rong, Xin Fang and Anyi Zhang, as well as Yunhao Lu of Zhejiang University in China. Their research was published in Nano Research in January.

Researchers have long attempted to use silicon, which is cheap and has a high potential capacity, in battery anodes. (Anodes are where current flows into a battery, while cathodes are where current flows out.) The problem has been that previous silicon anode designs, which were basically tiny plates of the material, broke down from repeated swelling and shrinking during charging/discharging cycles and quickly became useless.

Last year, Zhou's team experimented with porous silicon nanowires that are less than 100 nanometers in diameter and just a few microns long. The tiny pores on the nanowires allowed the silicon to expand and contract without breaking while simultaneously increasing the surface area – which in turn allows lithium ions to diffuse in and out of the battery more quickly, improving performance.

Though the batteries functioned well, the nanowires are difficult to manufacture en masse. To solve the problem, Zhou's team took commercially available nanoparticles—tiny silicon spheres—and etched them with the same pores as the nanowires. The particles function similarly and can be made in any quantity desired.

Though the silicon nanoparticle batteries currently last for just 200 recharge cycles (compared to an average of 500 for graphite-based designs), the team's older silicon nanowire-based design lasted for up to 2,000 cycles, which was reported in Nano Lett last April. Further development of the nanoparticle design should boost the battery's lifespan, Zhou said.

"The easy method we use may generate real impact on battery applications in the near future," Zhou said.

Future research by the group will focus finding a new cathode material with a high capacity that will pair well with the porous silicon and/or nanoparticles to create a completely redesigned .


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Who killed the graphite anode? Researchers move silicon anode li-ion battery technology forward

Journal information: Nano Research

Citation: Researchers developed cheap, strong lithium-ion battery (2013, February 12) retrieved 19 May 2019 from https://phys.org/news/2013-02-cheap-strong-lithium-ion-battery.html
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Feb 12, 2013
li-imide's time in the sun was short. :p

Maybe the same anode is applicable there.

Feb 12, 2013
(Anodes are where current flows into a battery, while cathodes are where current flows out.)


What?

I'm pretty sure both the anode and the cathode see current both ways, because you have to complete the circuit for electricity to flow.

which in turn allows lithium ions to diffuse in and out of the battery more quickly


...I'm pretty sure the lithium ions never leave the battery either.

This is a horribly written article.

Feb 12, 2013
@Eikka - Basically correct.
Lithium ions don't leave the battery. In normal operation lithium ions migrate from the anode to the cathode, creating a positive voltage there. Electrons are prevented from migrating with the ions, so the electrons flow from the anode into the rest of the circuit, and electrons flow back into the cathode to to neutralize the ions.
Electrons are negative and by convention current is positive so 'current' flows the opposite way. Thus during normal operation current flows only one way, into the anode (opposite from the electron flow.
However during charging of the battery the process is reversed, so if charging is included then yes, both electrodes see the current both ways.

Feb 13, 2013
These claims are frequently made to lure investors. I'll believe it when I see it!

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