What Are Physical Batteries
Physical batteries are batteries that generate electrical energy without chemical reactions. They use light or heat to obtain electrical energy. Solar, thermal, and nuclear batteries are examples of physical batteries.
Batteries are broadly divided into physical and chemical. Chemical batteries convert chemical reactions into electrical energy. Chemical batteries include primary batteries, secondary batteries, and fuel cells. Primary batteries include alkaline, manganese, and lithium dry batteries, while secondary batteries are rechargeable batteries, such as lead-acid batteries and alkaline batteries.
Uses of Physical Batteries
Physical batteries output electrical energy through the physical transfer of electrification, like semiconductors, without the use of chemical processes. Solar cells are a typical example of physical batteries.
Photovoltaic power generation has been in the limelight in recent years as a means of solving environmental problems, and the production of solar cells for industrial and residential use is rapidly increasing under government subsidies. In general, the majority of solar cells are installed on roofs or on land, where they can receive sufficient solar radiation to maximize their power generation capacity.
Principle of Physical Batteries
Solar cells have been attracting attention as physical batteries in recent years. Solar cells are made of semiconductors, which absorb sunlight and convert it into electrical energy. Despite the name “battery,” they do not have a storage function. The semiconductor atoms that make up a solar cell generate electrons and holes when they are exposed to sunlight.
A solar cell is composed of a P-type semiconductor and an N-type semiconductor superimposed on each other, with holes collecting in the P-type semiconductor and electrons in the N-type semiconductor. This generates a voltage between the holes and electrons, similar to that of a dry cell. Electricity can be extracted by connecting wires to the P-type semiconductor, which serves as the positive electrode, and the N-type semiconductor, which serves as the negative electrode.
There are several types of solar cells, which can be broadly classified into two types: silicon-based and compound-based. Each has different performance and characteristics, and the two types widely used for industrial and residential applications are silicon-based monocrystalline and polycrystalline. Compound monocrystalline solar cells have high power generation efficiency but are expensive, so they are often used for space applications such as satellites.