Characterization of Flowing Aqueous Solid Dispersions of Electroactive Lithium-Ion Battery Materials

While there are many material characterization techniques that are employed for the quality control processes of lithium-ion battery active material powders, eventually the materials must be validated electrochemically in battery cells. This requires making the cells including slurry mixing, slurry coating and drying, electrode calendering and pairing, and final cell assembly. Fabricating cells requires significant equipment and material expense and, in some cases, significant time. Additionally, the cells must be electrochemically tested which depending on the protocol can take multiple days. A technique that provides insights into the electrochemical properties of battery materials without cell fabrication and electrochemical evaluation could improve battery active material powder quality control and potentially reduce the time and cost involved in material validation. Our lab has been working on a technique where dispersions of battery active materials are evaluated electrochemically during collisions with current collectors. The technique has been referred to as dispersed particle resistance (DPR), and in previous studies we have shown that DPR measurements provide an indicator of the rate capability of lithium-ion battery active materials. DPR has a significant advantage with regards to timescale for material evaluation because the method takes only a few minutes and has the option of high throughput analysis due to a flow-through configuration. We have also adapted the technique to characterization of the particles in aqueous dispersions, and in this presentation we will demonstrate that the technique is effective with aqueous dispersions of cathode materials, including water-sensitive layered metal oxides with high nickel content such as LiNi0.8Co0.1Mn0.1O2.