New material promises better batteries

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BERKELELY, Calif., Sept. 23 (UPI) -- Scientists in California say a new material could allow lithium-ion batteries in cellphones, laptops and the newest electric cars to store more energy.

Researchers at the Lawrence Berkeley National Laboratory are focusing on the anode, a critical component for storing energy in such batteries.

Scientists at the U.S. Department of Energy facility have designed a new kind of anode that can absorb eight times the lithium of current designs and maintain its greatly increased energy capacity after more than a year of testing and hundreds of charge-discharge cycles, a laboratory release said Friday.

At the heart of the advancement is a polymer material that conducts electricity and binds closely to lithium-storing silicon particles, even as the particles expand to more than three times their volume during charging and then shrink again during discharge.

"High-capacity, lithium-ion anode materials have always confronted the challenge of volume change -- swelling -- when electrodes absorb lithium," laboratory researcher Gao Liu said.

This kind of swelling quickly breaks the electrical contacts in the anode, researchers said.

"Most of today's lithium-ion batteries have anodes made of graphite, which is electrically conducting and expands only modestly when housing the ions between its graphene layers," Liu said.

A major benefit of the new polymer anode material is that in addition to its superior performance it is economical, he said.

"Using commercial silicon particles and without any conductive additive, our composite anode exhibits the best performance so far," Liu said. "The whole manufacturing process is low cost and compatible with established manufacturing technologies."