不同粒径浆料混配对磷酸铁锂表征性能的影响OA

This study systematically investigates the influence of slurry mixing ratios with different particle sizes on the physicochemical and electrochemical properties of lithium iron phosphate(LiFePO4).Six groups of LiFePO4 samples with varying mixing ratios were synthesized via the high-temperature solid-state method.Comprehensive characterization was performed,including particle size distribution,specific surface area(BET),resistivity,tap density,iron dissolution rate,residual carbon content,and micromorphology.Charge/discharge specific capacity and rate performance were also evaluated.Slurries with different grinding particle sizes exhibit distinct specific surface areas,which significantly affect the reaction activity and agglomeration behavior of the materials.Consequently,post-sintering particle size shows marked differences:slurries with smaller initial particle sizes tend to form larger particles after sintering,while those with larger initial particle sizes yield smaller particles.Samples prepared from finer-particle slurries exhibit lower residual carbon content,reduced residual alkali,and poorer carbon coating,resulting in higher resistivity and elevated iron dissolution rates.Conversely,samples derived from coarser-particle slurries demonstrate higher residual carbon content,increased residual alkali,superior carbon coating,lower resistivity,and reduced iron dissolution.As the proportion of finer-particle slurry increases,the specific surface area(BET),residual carbon content,and pH value show negative correlations,while resistivity and iron dissolution rate exhibit positive correlations.This study proposes a"low-activity large particles+high-activity small particles"grading strategy,providing a theoretical foundation for optimizing the tap density and rate performance of LiFePO4.