Conductive Carbons by Design: Electrochemically Tailored Carbon Nanotube Conductive Additives for High Rate Battery Electrodes

With the electrification of transportation, the increased number of portable and connected devices, and the modernization of our grid to include energy storage coupled with renewable energy sources, increased demands of power, energy, lifetime, cost, and safety performance metrics for electrochemical energy storage are at an all-time high. Specifically of interest to the US DOE Vehicle Technologies office, advanced electrochemical energy storage is of critical importance to power our increasing transportation demands while simultaneously cutting back on transportation-related emissions. In conventional battery electrodes, low electronic conductivity of the cathode material prohibits fast charging and discharging of the cell and limits the thickness of cathode loadings onto current collectors, which lowers overall packaged cell-level energy density. To increase electronic conductivity, conductive additives such as carbon black, (CB) are utilized at mass loadings of 2-5 wt.%. Recently, 1D carbon nanotubes (CNTs) have been demonstrated as a superior additive compared to carbon black due to “line-to-line” contact with active materials compared to the “point-to-point” contact of CB. The 3D network produced with CNT-based additives in battery cathodes has been shown to facilitate higher active cathode mass loading, thicker cathodes that promote higher cell-level energy density, and high rate performance extreme fast charging rates. However, the core limitation for commercial adoption of these high performance additives is their extreme high cost and poorly scalable integration into existing manufacturing techniques. To address these challenges, in this proposal we will apply SkyNano’s patent-pending technology to synthesize crystalline CNT additives tailored toward optimized high voltage battery cathodes. SkyNano’stechnologyhingesonanovel electrochemical manufacturing method for CNTs that converts electrical energy, low-cost and earth abundant metals for catalysts, and ambient carbon from the air into highly valuable CNTs at energy efficiency greater than 90%. This produces CNTs that can be tailored in diameter and crystallinity at cost levels 10 – 1000X lower than CNTs produced in conventional gas phase chemistries and available on the commercial market today. By leveraging SkyNano’s technology, we can controllably design and manufacture the CNT additive to optimize the cathode material assembly, which will simultaneously maximize the energy density and fast charging capability, while minimizing inactive mass of the conductive