Engines and transmissions, lithium batteries, etc.
1. The heart of an electric hand drill is the electric motor, which converts electrical energy into mechanical energy to rotate the drill bit.
2. As the main power supply device of a hand drill, lithium batteries provide current to the motor to operate. Lithium batteries have the advantages of high energy density, light weight and long life, and are often used. in portable electronic devices.
1. Advantages:
1. Improved safety performance: The P-O bond in lithium iron phosphate crystal is stable and not easy to decompose even at high temperatures or overcharge. Like lithium cobalt oxide, the structure will collapse and generate heat or form a strong oxidizing substance, so it has good safety.
2. Improved service life: Lithium iron phosphate battery refers to a lithium-ion battery using lithium iron phosphate as the positive electrode material. The lifespan of long life lead acid batteries is about 300 times and the maximum is 500 times, while the lifespan of lithium iron phosphate batteries reaches more than 2000 times and can reach 2000 times with one standard charge (5 hours). rate).
2. Disadvantages:
1. The plug density of the positive electrode of the lithium iron phosphate battery is small, and the density is generally around 0.8 to 1.3. Big size.
2. During the sintering process when preparing lithium iron phosphate, iron oxide can be reduced to elemental iron in a high temperature reducing atmosphere. Elemental iron can cause micro-short circuits in the battery.
Principle and structure of the batteryu lithium iron phosphate:
1. Commercial lithium iron phosphate battery generally consists of the following parts: positive electrode material (lithium iron phosphate), negative electrode material (graphite), as well as aluminum foil (positive), copper foil (negative) as positive and negative current collectors, and positive and negative electrode tabs (i.e. current collector outputs).
2. There are also separators, electrolytes, aluminum-plastic films and battery protection plates. It adopts winding type and is made into 18650 type battery.
3. The principle is that during discharge, Li ions migrate from the negative electrode to the positive electrode; and during charging, Li ions migrate from the positive electrode to the negative electrode. .