SBIR-STTR Award

Development of superior Li-ion batteries (LIBs) is a critical part of the US Department of Energy’s (DOE) mission to improve the economic, social, and environmental sustainability of electric vehicles (EV). This mission, “EV Everywhere Grand Challenge” seeks to reduce the cost of the EV batteries from the current more than $250/kWh to less than $125/kWh by 2022. To achieve this goal, the materials and manufacturing costs of the battery components must be reduced significantly. This is especially true for the cathode materials and their manufacturing methods, which account for approximately 30% of the total cost of the state-of-the-art LIB. The large percentage of the total cost is due to the high cost of the components of the cathode materials and their complex manufacturing methods. Layered Ni-rich oxides of the type Li(Ni1-x-yMnxCoy)O2 with Ni greater than 0.6 (Ni-rich NMC) have recently gained prominence because of their high capacities (200 to 225 mAh/g), high-voltage cyclability (2.0 to 4.5 V), and low cost. Significantly improved performance of hierarchically structured (compositionally gradient) Ni-rich NMC (Ni equals 0.4) cathode powders exhibiting local elemental segregation have been reported through spray pyrolysis. We believe that both the chemistry (all-nitrate precursors) and the method (horizontal spray pyrolysis) can be further improved and developed into a scalable manufacturing method for the new generation of low-cost, high-capacity, high-voltage Ni-rich NMC cathode materials, such as Li(Ni1-x-yMnxCoy)O2 (Ni greater than 0.6). These cathode materials will contain the desired compositional gradient and surface chemistry that will enable superior long-term performance. Hazen Research, Inc., in collaboration with National Renewable Energy Laboratory (NREL), will develop and demonstrate a high-throughput and scalable manufacturing method for the production of Ni-rich NMC cathode materials of the type Li(Ni1-x-yMnxCoy)O2 (Ni greater than 0.6) by combining a vertically fed spray pyrolysis with a fluidized-bed reaction in a single reactor. This approach will mitigate the possibility of agglomeration, and uniform Ni-rich NMC cathode particles can be produced in a single reactor, making it a continuous production process. The Li(Ni1-x-yMnxCoy)O2 (Ni greater than 0.6) particles having a Ni-rich core, but with a Mn-rich surface, will be produced through rationally developed precursors for spray pyrolysis. The proposed single solution precursors will use Li, Ni, Mn, and Co starting materials with similar decomposition temperatures (nitrates) along with minor components of Ni and Mn materials with increasing decomposition temperatures (carboxylates and fluorinated carboxylates) maintaining the overall stoichiometry. This novel inorganic–metalorganic composite precursor is expected to form particles with the targeted Ni-poor and Mn-rich surfaces upon spray pyrolysis. Amorphous powders formed during spray pyrolysis can be reacted further and crystallized to uniform particles with increased tap density through fluidized-bed reactor processing. Our approach, combining spray pyrolysis and fluidized-bed reaction in a single reactor, using an inorganic–organic precursor, is novel and is expected to lead to a low-cost manufacturing method for the production of these next-generation cathode materials. Along with its high capacity, the Ni-rich NMC cathode particles of Li(Ni1-x-yMnxCoy)O2 (Ni greater than 0.6) produced by this combined method are expected to retain the compositional gradient favorable for the high voltage (2.0 to 4.5 V) and stable cycling performance. During this Phase 1 effort, the Hazen–NREL team will perform the following tasks: Develop inorganic–metalorganic precursors for the spray pyrolysis to produce compositionally gradient Ni-rich NMC, Li(Ni1-x-yMnxCoy)O2 (Ni greater than 0.6) cathode powders; Design, build, and demonstrate a combined spray pyrolysis and fluidized-bed reactor for the manufacturing of Ni-rich NMC cathode powders with capacity more than 200 mAh/g and cycling between 2.0 and 4.5 V; Validate greater than 200 mAh full cells (with more than 95% capacity retention over 250 cycles) using the cathode powders produced under the recommended USABC testing protocols. The EV market is estimated to be $12.8 billion in 2017, with an annual growth close to 60% from 2008–2017; the North American portion of the market alone is expected to reach $5.8 billion in revenue. Through an improved and scalable manufacturing of the low-cost high-performance Ni-rich NMC cathode powders, our approach will directly influence this market and significantly reduce the cost of state-of-the-art EV batteries. The demand for layered LiMO2 (M=Co/Mn/Ni/Al) type cathode powders was approximately 75,000 t in 2014 and is projected to be approximately 225,000 t in 2025, representing an approximate 200% increase in demand in less than 10 years. The technology developed under this proposal is directly applicable to the manufacturing of the materials with huge market demand. The proposal will further advance EV battery technology and assist in accomplishing the following: Improve the competitive position of United States industry in the field of advanced materials and manufacturing to create jobs; Enhance energy security by reducing dependence on foreign oil; Save money by cutting fuel costs for American families and businesses; and Protect health, environment, and safety by mitigating the effect of energy production on climate change.