LiFePO₄ (LFP) primary particles and secondary agglomerates have been processed into water- and solvent-based cathodes. By means of neutron and X-ray diffraction it was found that no structural changes of LiFePO₄ occurred upon water- and solvent-based slurry preparation. Electrochemical characterization was carried out with full-cells and a distinct influence of particle morphology was observable. Water-based processing of primary particles leads to deficits in electrochemical performance while secondary agglomerates are non-sensitive to water during processing. In the presence of water, high mechanical stress during slurry preparation causes a partial detachment of carbon coating. However, this effect is negligible for secondary agglomerates since only surface particles are exposed to mechanical stress. Due to longer diffusion paths and the fact that secondary agglomerates represent a micro-heterogeneity in the cathode, the C-rate capability of secondary agglomerates is slightly lower than that of primary particles. This paper demonstrates that for any high energy application with moderate C-rates, secondary agglomerates hold a great potential for environmentally friendly and cost-efficient water-based cathode production.

LiFeMnPO₄ secondary agglomerates have been aged under different temperature and moisture conditions. The aged and pristine powder samples were then processed to water- and solvent-based cathodes. Structural studies by means of neutron and X-ray diffraction revealed that neither ageing nor water-based processing significantly modified the crystal structure of LiFeMnPO₄ secondary agglomerates. Electrochemical characterization was carried out with full-cells. It was found that long-term cycling is similar independent of the solvent used for slurry preparation. Full-cells assembled with water-based cathodes show a better C-rate capability due to a more homogeneous distribution of cathode constituents compared to solvent-based ones. In no case was any negative effect of initial active material ageing on the electrochemical performance found. During ageing and processing, LiFeMnPO₄ is effectively protected by carbon coating and water can be completely removed by drying since it is only reversibly bound. This contribution shows that LiFeMnPO₄ secondary agglomerates allow simplified active material handling and have a high potential for sustainable water-based electrode manufacturing.