Cathode slurry is a typical high-solid-content system. Particles of lithium iron phosphate and ternary materials are fine and high in specific gravity, which tend to agglomerate when mixed with binders and solvents. If air bubbles are trapped in the slurry, pinholes will form on the coated electrode sheet, and fluctuations in areal density will directly impair capacity consistency. During the ramp-up phase of cathode production lines, slurry batches must remain stable. Otherwise, faster capacity expansion will amplify quality variations, and this is often the bottleneck on material manufacturers’ schedules.

News on October 22: GCL Technology plans to acquire an 81.91% equity stake in GCL Lithium for 2.5 billion RMB to consolidate its cathode material business. Its 150,000-ton capacity at the Renshou base has reached full production, and long-term orders have been secured from leading customers including CATL. After integration, the total capacity will reach 350,000 tons. As cathode materials move from full production to consolidated capacity expansion, outsourced and in-house production lines run in parallel at full capacity, while new line ramp-up and stable supply from existing lines proceed side by side. Whether slurry process development can keep pace with production line construction is the key schedule item being reviewed by material suppliers.

Cathode material manufacturers usually carry out sample verification based on mass-production formulas to define the mixing and defoaming process window before scaling up parameters. SIENOX has recently received inquiries from multiple cathode material manufacturers, who aim to complete slurry defoaming validation before expansion and control gas content within target limits. The SIENOX MIX1000PLUS adopts a planetary structure with revolution and rotation. Rotational shear and revolutionary stirring work together to rapidly wet high-solid-content cathode powder and disperse agglomerates. Defoaming proceeds simultaneously under vacuum (-98 KPa) with a maximum speed of 2000 rpm; temperature control is available as a customized option. Its 1000 mL processing volume supports pilot testing and pre-mass-production verification for cathode slurry, and test results provide references for parameter setting of scaled-up equipment.

Tested slurry shows no agglomeration or visible bubbles, with stable areal density and batch-to-batch performance. The timetable for cathode material expansion includes full-capacity operation and business consolidation. Vacuum defoaming mixers are widely proven for lithium iron phosphate systems. Process validation for battery slurry mixers and slurry defoamers is recommended prior to production line construction. Relevant statements are compiled from public industry information, and actual test data shall be subject to customer trials.