Smartphone battery life is one of the biggest sore points, and there has not been much progress on this front unlike the rest of the technology used in the phones.
However that is likely to change as scientists at the Department of Energy’s (USA) Oak Ridge National Laboratory (ORNL) have designed and tested an all-solid lithium-sulfur battery with approximately four times the energy density of conventional lithium-ion technologies that power today’s electronics.
Two of the biggest advantage of this battery apart from better storage will be that it is made of Sulfur which is abundant and very cheap and scientists have also addressed flammability concerns (exploding batteries) experienced by other chemistries.
“Our approach is a complete change from the current battery concept of two electrodes joined by a liquid electrolyte, which has been used over the last 150 to 200 years,” said Chengdu Liang, lead author on the ORNL study published this week in Angewandte Chemie International Edition.
Scientists have been excited about the potential of lithium-sulfur batteries for decades, but long-lasting, large-scale versions for commercial applications have proven elusive. Researchers were stuck with a catch-22 created by the battery’s use of liquid electrolytes: On one hand, the liquid helped conduct ions through the battery by allowing lithium polysulfide compounds to dissolve. The downside, however, was that the same dissolution process caused the battery to prematurely break down.
The ORNL team overcame these barriers by first synthesizing a never-before-seen class of sulfur-rich materials that conduct ions as well as the lithium metal oxides conventionally used in the battery’s cathode. Liang’s team then combined the new sulfur-rich cathode and a lithium anode with a solid electrolyte material, also developed at ORNL, to create an energy-dense, all-solid battery.
“This game-changing shift from liquid to solid electrolytes eliminates the problem of sulfur dissolution and enables us to deliver on the promise of lithium-sulfur batteries,” Liang said. “Our battery design has real potential to reduce cost, increase energy density and improve safety compared with existing lithium-ion technologies.”
The team’s all-solid design also increases battery safety by eliminating flammable liquid electrolytes that can react with lithium metal. Chief among the ORNL battery’s other advantages is its use of elemental sulfur, a plentiful industrial byproduct of petroleum processing.
“Sulfur is practically free,” Liang said. “Not only does sulfur store much more energy than the transition metal compounds used in lithium-ion battery cathodes, but a lithium-sulfur device could help recycle a waste product into a useful technology.”
Although the team’s new battery is still in the demonstration stage, Liang and his colleagues hope to see their research move quickly from the laboratory into commercial applications. A patent on the team’s design is pending.