Preparation of Highly Crystalline Nickel Nanopowder for Ultrathin Multilayer Ceramic Capacitors: Use Sodium Carbonate as Isolation Phase to Avoid High‐Temperature Sintering of Nickel Nanoparticles

Multilayer ceramic capacitors (MLCCs) are widely used passive components in modern electronics and have continuously evolved toward thinner dielectric layers, greater miniaturization, and higher capacitance. The Ni powder used in MLCCs must exhibit high crystallinity, small particle size, and excellent dispersibility. Achieving high crystallinity in Ni nanopowders requires preparation temperatures above 600 °C, but preventing sintering and grain growth at such temperatures remains a significant challenge. In this study, a salt containing composite solution precipitation method to coprecipitate Na 2 CO 3 and a nickel precursor is applied, achieving uniform nanometer scale isolation of the precursor by Na 2 CO 3 and effectively inhibiting nanoparticle sintering during high‐temperature treatment. This approach produced Ni nanoparticles with a uniform diameter of 35 nm, enhanced dispersibility, and superior oxidation resistance (onset oxidation temperature of 330 °C). Moreover, the method is cost‐effective and readily scalable for large‐scale production.