Applying Established Water-Based Binders to Aqueous Processing of LiNi0.83Co0.12Mn0.05O2 Positive Electrodes

The combination of two different binders: styrene-butadiene rubber (SBR) and polyacrylic acid (PAA), in combination with carboxymethylcellulose (CMC) has been investigated for aqueous electrode preparation of LiNi0.83Co0.12Mn0.05O2 positive electrodes. The use of Ni-rich active materials in Li-ion batteries is becoming industry standard, however, such Ni-rich cathode materials are sensitive to water, which makes the aqueous electrode manufacturing especially challenging and based on industry-information even impossible. The preparation of aqueous Ni-rich electrodes with areal capacities of 2.7 mAh cm(-2) and densities of up to 3.5 g cm(-3) was investigated and optimized. The electrochemical evaluation in bi-layer pouch cells showed that the performance depends heavily on the individual combination of binders. Using PAA binders, the best electrode reached 80% capacity retention only after 470 cycles. In contrast, the best electrode with SBR binder performed very similar to the PVdF reference electrode in view of rate capability and a specific 1 C capacity with 177 mAh g(CAM) (-1) compared to 179 mAh g(CAM) (-1) of the PVdF reference electrode. In addition, this SBR-based electrode showed excellent cycling stability at 1 C/1 C with capacity retention of 84% after 1,000 cycles; therefore, matching typical requirements for such electrodes in electric vehicle batteries.

Automated summary

The study investigated the preparation of aqueous Ni-rich electrodes using a combination of SBR and PAA binders, achieving areal capacities of 2.7 mAh cm(-2) and densities up to 3.5 g cm(-3). The electrochemical evaluation showed that the performance heavily depends on the individual combination of binders, with the SBR-based electrode demonstrating excellent cycling stability at 1 C/1 C with capacity retention of 84% after 1,000 cycles.