Researchers from Samsung Advanced Institute of Technology (SAIT) said they have developed technology that uses silicon cathode material coded with high-crystalline graphene to produce batteries with twice as much capacity as ordinary lithium-ion batteries.
7/21/15 5:00 am chumakdenis 1
Researchers from Samsung Advanced Institute of Technology (SAIT) managed to make a real breakthrough: they have developed material that doubles the power capacity of lithium-ion batteries.
To be more exact, the team of scientists have developed a technology to make a silicon cathode material for coating high crystal graphene on a silicon surface to realize an energy density almost two times more than that of existing lithium batteries.
Just to remind you: silicon realizes more than 10 times the power capacity compared with graphite, but has never been used before for technological problems over drastic degradation of battery life --discharge cycles seriously weakens its competitiveness in the volumetric energy density and cycle life.
Luckily to us, this problem has been solved by the R&D center of Samsung Electronics.
The graphene layers anchored onto the silicon surface accommodate the volume expansion of silicon via a sliding process between adjacent graphene layers. When paired with a commercial lithium cobalt oxide cathode, the silicon carbide-free graphene coating allows the full cell to reach volumetric energy densities of 972 and 700Whl−1 at first and 200th cycle, respectively, 1.8 and 1.5 times higher than those of current commercial lithium-ion batteries. This observation suggests that two-dimensional layered structure of graphene and its silicon carbide-free integration with silicon can serve as a prototype in advancing silicon anodes to commercially viable technology.
Advantages of newly-created material
This material has up to four times the capacity compared with graphite and can double the energy density of ordinary lithium-ion batteries, the institute said.
"The theoretical gravimetric capacity of silicon (Si) reaches almost 4,000mAhg−1. This unparalleled value has stimulated the battery community to invest considerable research efforts because the high gravimetric capacity enables one to increase the energy densities of lithium-ion batteries (LIBs) significantly, and thus bring future LIB applications, such as electrical vehicles, to a reality. In the past decade, diverse advanced electrode structures and binder designswere developed to resolve chronic capacity fading issues originating from the large volume change of Si, leading to substantially improved cycling performance even over thousands of cycles. In spite of the promising gravimetric value and substantial progress in cycle life, most of Si anodes demonstrated to date have focused primarily on the gravimetric capacity but have not offered a similar promise in their volumetric capacity because existing electrode designs rely on pre-defined void space to accommodate the volume expansion of Si. In many LIB applications including portable electronics, however, the volumetric energy density is a critical parameter in determining battery performance. Together with a relatively inferior cycle life, weak volumetric energy density is presently a major bottleneck in implementing Si anodes in commercial cells. To meet this critical demand, Si anode technology needs to be revisited with different electrode designs that offer stable cycling performance while the electrode volume is minimized".
*Patents covering the new technology have been applied for in Korea, China, Europe and the United States.
All-new batteries in EVs
The research team said the new technology is expected to enhance the performance of mobile devices and electric vehicles.
"The research has dramatically improved the capacity of lithium-ion batteries by applying a new synthesis method of high-crystalline graphene to a high-capacity silicon cathode," said Son In-hyuk, a professional researcher at SAIT.
"We will continue to improve the secondary cell technology to meet the expanding demand from mobile device and electric vehicle markets."
Well, that's very cool of them, especially if we'll take into account the fact that these batteries might replace existing lithium-ion batteries, which were developed in a way of extending the capacity rather than increasing the life and density owing to limitations of material itself.
However, don't expect it to happen soon - it will take at least two years for Samsung Group to hit these batteries into production - red tape, rivals, commercialization and a bunch of other stuff.
Nevertheless, we're happy with the fact that such researches are done and we'd like to wish SAIT research team good luck.
The more innovations are, the better life is.
*The research result was published in the online science journal Nature Communications.
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