In recent years, with the development trend toward high capacity, small size, and high reliability, the production cost of MLCCs has been increasing. Using nickel as the internal electrode and copper as the terminal electrode is gradually replacing precious metal electrodes, and becoming the development trend of MLCCs, and the demand for nano nickel powder has also been growing.

Characteristics and Applications of Nano Nickel Powder

1. Nano nickel powder has a small size, large specific surface area, and a significant proportion of atoms at the grain boundaries and surfaces within the crystal structure. It possesses performance advantages such as high-efficiency photocatalysis, high conductivity, and magnetic properties, widely used in fields such as electronics, chemicals, environmental protection, and energy. 

2. Nano nickel powder can be used in catalytic reactions, such as serving as an anode catalyst in fuel cells.

3. Nano nickel powder has excellent conductivity, good stability, and low sintering temperature, widely used in various conductive slurries and battery electrodes.

4. Due to its unique magnetic properties, nano-nickel powder can be used to prepare magnetic fluids (which exhibit superior performance to ferrites) for use in damping devices and other fields.

5. The good dispersibility and easy separability of nano nickel powder make it suitable for use in the fields of biomarkers and bioseparation.

Nano Nickel Powder for MLCC Internal Electrodes

The earliest internal electrode paste used in MLCCs was silver paste containing palladium. However, as a precious metal, palladium is expensive, leading to high production costs for MLCCs. To reduce costs, metal internal electrodes represented by copper and nickel emerged and are now the most widely used. Although copper has a lower resistivity and lower cost, its low co-firing temperature requires a highly sophisticated preparation process. Additionally, copper paste is chemically active and oxidizes rapidly in air, causing a significant decline in electrode conductivity. In contrast, nickel, which is abundant, as a conductive paste not only offers excellent conductivity but also has a preparation cost far lower than traditional precious metals. 

Current Status of Research on Nano Nickel Powder for MLCCs

As electronic devices continue to evolve toward miniaturization and higher functionality, the demand for smaller and more numerous electronic components is also increasing. This trend is particularly pronounced in the expanding market for mobile communication devices, which has driven a significant reduction in the size of MLCCs. As a result, the demand for internal electrode materials in MLCCs has shifted toward materials that are smaller in size, uniformly distributed, and exhibit excellent dispersibility and high crystallinity.

In the manufacturing process of MLCC internal electrodes, the uniformity of the size of nano nickel powder and its dispersion in the slurry are critical factors determining the continuity and roughness of the final sintered electrode. If the crystallinity of the metal nanoparticles is poor, volume contraction may occur during sintering, leading to electrode layer fractures and poor conductivity of the sintered electrodes. Additionally, since the process involves high-temperature degassing and sintering to form the electrode layer and dielectric layer, the internal electrode material must possess adequate oxidation resistance.