The smartphone in your pocket is a complex electronic system with many different functions powered by the same built-in battery.
An electronic circuit consists of independent electronic components, such as resistors, transistors, capacitors, inductors, and diodes, connected through wires or circuit boards. Capacitors have the ability to store charges, or "containers", much like small rechargeable batteries.
In consumer electronics products, there are usually hundreds of micro-capacitors, and in high-end smartphones such as the iPhone, there are more than 1000 micro-capacitors. They are called multi-layer ceramic capacitors (MLCC), which can be as small as sand grains on your favorite holiday beach. Their function is to decouple the subcircuit from the power fluctuation caused by the activity of another subcircuit.
Nickel reduces the size of MLCC by thinning the insulation layer thickness and keeping the capacitance constant. In 2020, 4800t nickel powder was used to produce sand-sized MLCC.
