Photo by Waldemar Brandt on Unsplash
Recently, the battery company StoreDot announced that it is developing a rapid-charging lithium ion battery pack for use in electric vehicles, that can be fully charged in about five minutes. Enquiring minds want to know how this is accomplished.
On its website, StoreDot states: “This optimized charging ability is achieved through an innovative electrode structure containing proprietary organic polymers with Metal Oxide compounds of the cathode that trigger the redox reactions. This solution enables ions to flow from a modified anode to a modified cathode at a speed that is much faster than existing technologies. Together with a proprietary separator and electrolyte, this new architecture delivers a high current and low internal resistance, with enhanced energy density and a prolonged battery life.” Therefore, it appears that StoreDot has at least modified the anode, the cathode, the separator, and the electrolyte of a conventional lithium ion cell. But in what ways?
An article published in The Guardian on January 19, 2021 (https://tinyurl.com/kf24c8me), states that StoreDot uses germanium nanoparticles in the anode in place of graphite and plans to replace these with silicon nanoparticles. A recently issued patent sheds more light on the anode structure. On January 26, 2021, StoreDot was issued U.S. Pat. No. 10,903,530 which describes anode active material particles being comprised of anode core materials surrounded by a porous graphite shell, where the anode core materials comprise silicon, germanium, tin, and possibly some other materials. According to the ‘530 patent, safety of the anode is improved by creating buffering zones around the active material particles that reduce the probability of lithium metallization and dendrite growth on the anode. According to the ‘530 patent, the buffering zones comprise the porous carbon shells which partially reduce lithium ions moving from the electrolyte into the anode active material, thereby preventing dendrite formation.
So, the anode in the StoreDot rapid charging battery is probably something like what is described above and in the ‘530 patent. However, it is still not clear what changes were made to the cathode, separator, and electrolyte, so this remains to be determined.
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