Multi-Layer Ceramic Capacitors (MLCCs) are fundamental components in the modern electronics industry. As MLCCs evolve towards higher capacitance and miniaturization, Base Metal Electrode (BME) technology has become the industry standard. In the BME system, nano nickel powder serves as the conductive phase for internal electrodes. Its physical morphology, trace impurity control, and phase purity directly determine the Insulation Resistance (IR) and yield of the capacitors.

Currently, the mainstream and highly reliable process for synthesizing high-performance nano nickel powder is the liquid-phase chemical reduction method. This process typically utilizes high-purity nickel salts as precursors. Under the action of a pure reducing agent, the nucleation and growth of metallic nickel particles are precisely controlled in a liquid-phase system. This synthesis pathway forms a strict physical and chemical logic loop with high-reliability MLCC manufacturing processes:

1. Controlled Liquid-Phase Growth and Thin-Layer Matching
   As MLCC ceramic dielectric layers approach sub-micron thicknesses, internal electrode thickness must scale down accordingly. The liquid-phase method precisely controls particle growth, yielding uniform particles with a D₅₀ between 100nm and 400nm. An extremely narrow particle size distribution (strictly controlling D_max) prevents oversized particles from puncturing the ceramic dielectric (causing short circuits) and avoids mismatched sintering shrinkage caused by excessive ultrafine particles.
    
2. Anti-Agglomeration, Trace Impurity Control, and Paste Rheology
   The extremely high surface energy of nano powders makes them highly susceptible to "hard agglomeration." During the drying and washing stages, advanced surface modification technologies must be applied to create steric hindrance, ensuring excellent dispersibility of the powder in the electronic paste. Concurrently, deep washing reduces trace anions (such as SO₄^2-, NO₃^-) to the ppm level, while core trace impurities are strictly controlled at C < 0.05% and Fe < 0.005%. These ultra-low impurity levels eliminate micro-pores and magnetic interference during high-temperature co-firing. Combined with high dispersibility, this thoroughly prevents paste "gelation" and imparts perfect thixotropy.
    
3. Core-Shell Passivation and High Saturation Magnetization
   Untreated nano-scale metals are highly pyrophoric. It is critical to introduce a dense Nickel Oxide (NiO) passivation shell approximately 2-5 nm thick. This uniform nano-scale film provides oxidation resistance during the initial binder burnout phase and prevents electrode delamination during co-firing above 1200°C in a weak reducing atmosphere. The nano nickel powder produced via this process achieves a saturation magnetization ≥ 45 emu/g. This key physical parameter directly proves high internal crystallinity and extreme metallic phase purity, ensuring the passivation layer is optimally thick without compromising sintered conductivity.
    
4. Safety and Compliance in Industrial Storage and Transport
   Based on their physicochemical properties, nano metal powders are strictly classified as Class 4.1 Flammable Solids in international logistics. In a standard industrial supply chain, such materials must utilize UN-certified hazardous goods packaging and remain sealed under the protection of inert gases (argon or nitrogen) to guarantee absolute safety during maritime transport and factory storage.

The Microscopic Foundation of Macroscopic Technology
The quality of nano nickel powder is not merely an art of chemical synthesis; it is the foundational support enabling the modern electronics industry to breach physical limits. From signal processing in 5G base stations and power control systems in Electric Vehicles (EVs) to high-frequency computing in AI servers, the stable operation of every high-performance MLCC relies entirely on the relentless pursuit of purity, particle size, and dispersibility at the materials level. Understanding these microscopic technical mechanisms is the first step in building a highly reliable electronic component supply chain and driving industry innovation.