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Two soylentils have submitted stories about improvements in lithium battery storage capacity. The first focuses on the cathode while the second features improvements in the anode.

Tripling the Energy Storage of Lithium-Ion Batteries

MrPlow writes:

Submitted via IRC for BoyceMagooglyMonkey

A collaboration led by scientists at the University of Maryland (UMD), the U.S. Department of Energy's (DOE) Brookhaven National Laboratory, and the U.S. Army Research Lab have developed and studied a new cathode material that could triple the energy density of lithium-ion battery electrodes. Their research was published on June 13 in Nature Communications.

"Lithium-ion batteries consist of an anode and a cathode," said Xiulin Fan, a scientist at UMD and one of the lead authors of the paper. "Compared to the large capacity of the commercial graphite anodes used in lithium-ion batteries, the capacity of the cathodes is far more limited. Cathode materials are always the bottleneck for further improving the energy density of lithium-ion batteries."

Scientists at UMD synthesized a new cathode material, a modified and engineered form of iron trifluoride (FeF3), which is composed of cost-effective and environmentally benign elements—iron and fluorine. Researchers have been interested in using chemical compounds like FeF3 in lithium-ion batteries because they offer inherently higher capacities than traditional cathode materials.

Source: https://www.bnl.gov/newsroom/news.php?a=112885

Turbocharge For Lithium Batteries

Arthur T Knackerbracket has found the following story:

A team of material researchers from Juelich, Munich, and Prague has succeeded in producing a composite material that is particularly suited for electrodes in lithium batteries. The nanocomposite material might help to significantly increase the storage capacity and lifetime of batteries as well as their charging speed. The researchers have published their findings in the journal Advanced Functional Materials.

"In principle, anodes based on tin dioxide can achieve much higher specific capacities, and therefore store more energy, than the carbon anodes currently being used. They have the ability to absorb more lithium ions," says Fattakhova-Rohlfing. "Pure tin oxide, however, exhibits very weak cycle stability—the storage capability of the batteries steadily decreases and they can only be recharged a few times. The volume of the anode changes with each charging and discharging cycle, which leads to it crumbling."

One way of addressing this problem is hybrid materials or nanocomposites—composite materials that contain nanoparticles. The scientists developed a material comprising tin oxide nanoparticles enriched with antimony, on a base layer of graphene. The graphene basis aids the structural stability and conductivity of the material. The tin oxide particles are less than three nanometres in size—in other words less than three millionths of a millimetre—and are directly "grown" on the graphene. The small size of the particle and its good contact with the graphene layer also improves its tolerance to volume changes—the lithium cell becomes more stable and lasts longer.

"Enriching the nanoparticles with antimony ensures the material is extremely conductive," explains Fattakhova-Rohlfing. "This makes the anode much quicker, meaning that it can store one-and-a-half times more energy in just one minute than would be possible with conventional graphite anodes. It can even store three times more energy for the usual charging time of one hour."

"Such high energy densities were only previously achieved with low charging rates," says Fattakhova-Rohlfing. "Faster charging cycles always led to a quick reduction in capacity." The antimony-doped anodes developed by the scientists, however, retain 77 % of their original capacity even after 1,000 cycles.

Original Submission #1  Original Submission #2