The low energy stored within current day batteries limits the size and weight of contemporary electronics ranging from consumer electronics to medical devices. A new generation of high energy density power packs is needed. In this project, the unprecedented ability of vanadium diboride to release an exceptional 11 electron per molecule yields an energy density substantially greater than that of lithium or zinc, and provides the opportunity to greatly enhance the energy density of power packs. Today's batteries and fuel cells deliver only one or two electrons per molecule. Remarkably, the 11e- storage capacity of vandium diboride is released over a flat, favorable, singular discharge voltage. Little is known regarding the limiting mechanisms of this unusual process. The unique electrochemical properties of VB2 will be explored in this project. This GOALI project is a collaborative university-industry effort to understand the unusual and promising redox storage process of new energy dense, multi-electron materials for batteries and fuel cells.
TECHNICAL DETAILS: In this project, the unprecedented ability of vanadium diboride to release an exceptional 11 electron per molecule will be explored to greatly enhance the energy density of power packs. This VB2 charge density is substantially greater than that of conventional battery anodes based on lithium or zinc. Remarkably, the 11e- storage capacity of vandium diboride is released over a flat, favorable, singular discharge potential plateau. Little is known regarding limiting mechanisms of this unusual process, and the unique electrochemical properties of VB2 nanoparticles will be explored in this project. This research, provides the first foray into the nano-domain of VB2 (anodic) electrochemistry. Stabilizing zirconia coated nanoparticle architectures will be studied to facilitate this unusual 11 electron anodic process and to formulate in a library of new VB2 nano-composites. A fundamental understanding of these processes will be developed towards the transformative goal of a new generation of power packs with several fold higher capacity than existing batteries and fuel cells. Cell configurations will be optimized to maximize the capacity of a VB2/air energy storage cell. This GOALI project is a collaborative university-industry effort to understand the unusual and promising redox storage process of new energy dense, multi-electron materials for batteries and fuel cells. The George Washington University (GWU) postdoctoral scholar and graduate and undergraduate researchers participating in this project will be trained in state-of-the-art fundamental electrochemistry at GWU and have the special opportunity to gain experience in the industrial R&D workplace through visits each year to the industry liason, Lynntech, Inc.
Multiple electron per molecule battery storage, which opens a pathway to higher capacity batteries, was explored. First the fundamental and practical chemistry of a new primary (single use) battery was developed of the vanadium diboride / air battery. This battery yields a highly unusual 11 electrons per VB2 molecule, each discharging at the same voltage plateau. The battery has ten-fold higher capacity than today's lithium-ion batteries, but is not rechargeable. New, effective syntheses were explored to make the VB2, including a effective nanoscopic synthesis of the VB2 from elemental vanadium and boron. Batteries constructed with nanoscopic VB2 yield 20% higher voltage and discharge more effectively at higher current densities than batteries containing larger (microscopic) particle size VB2. A video was also published (in the Journal of visualized experiments) detailing how to construct and test the VB2 battery. Towards the end of this project, a new class of multiple electron rechargeable batteries was discovered and named Molten Air Batteries. As with the room temperature battery, these batteries have the highest energy storage capabilities of any battery, and use air (oxygen) as one of the two reactants, but operate at higher temperature with molten salts that allows them recharge. Three examples of the new battery class were presented, the Molten Iron, Molten Carbon and Molten VB2 Air batteries. The work was published in Energy and Environmental Science (6, 3646-3657, 2013) and a popular description of this discovery was presented by the National Science Foundation (at www.nsf.gov/discoveries/disc_summ.jsp?cntn_id=131828). Broader impacts of this project included dissemination of a transformative process for electrochemical energy storage, and training the next diverse generation of renewable energy scientists. Students had the opportunity to work in both academic and industrial research laboratories (at both the Principal Investigator facilities at George Washington University and at the project's industry partner, Lynntech Inc.'s R&D facilities). High School, undergraduate and graduate students and postdoctoral fellows were exposed to training in a wide venue of electrochemical experiences. New, highest energy capacity batteries were discovered and the envelope of scientific knowledge was expanded to include the field of multi-electron energy storage.
