Increasing electrode mass loading is an effective route to improving cell-level energy density without altering material chemistry, yet conventional slurry-casting fabrication is constrained by drying-induced heterogeneities that impair structural integrity and electrochemical performance. Here, we present a capillary-bridged slurry engineering strategy that enables scalable fabrication of high-mass-loading electrodes with uniform composition and robust structure. Introducing a trace amount of an immiscible secondary solvent generates capillary bridges, forming percolated particle networks that suppress directional migration of electrode components during drying. Applied to Ni-rich cathodes, this method achieves uniform through-thickness composition and redox homogeneity at thicknesses exceeding 400 μm, delivering areal capacities up to 27 mAh cm–2. It also enhances manufacturing reliability by ensuring thickness uniformity over large areas, reducing scrap losses, and increasing electrode production yield, thereby lowering cell-level costs. This approach is compatible with existing slurry-casting lines, offering a scalable, cost-effective pathway to energy-dense battery electrodes.