Nickel cadmium batteries and lithium batteries have their own advantages, and the differences between the two are as follows:

There are seven main differences:

1. Different constituent materials: Lithium batteries use carbon material (graphite) as the negative electrode and lithium containing compounds as the positive electrode; The positive electrode of nickel cadmium batteries is composed of active materials such as nickel oxide powder and graphite powder, while the negative electrode is composed of active materials such as cadmium oxide powder and iron oxide powder.

2. The working principle is different: lithium batteries are more like charge containers and do not rely on electrochemical reactions during operation. When charging the battery, lithium ions are generated on the positive electrode, and the generated lithium ions move through the electrolyte to the negative electrode. As the negative electrode, carbon has a layered structure with many micropores. The lithium ions that reach the negative electrode are embedded into the micropores of the carbon layer. The more lithium ions embedded, the higher the charging capacity. Similarly, when discharging the battery (i.e. the process of using the battery), the lithium ions embedded in the negative carbon layer are released and move back to the positive electrode. The more lithium ions return to the positive electrode, the higher the discharge capacity. The operation of nickel cadmium batteries requires electrochemical reactions. During charging, electrons travel along the wire to the cathode, where they react with nickel dioxide and water in a sodium hydroxide solution to form nickel hydroxide and hydroxide ions. Electrical energy is converted into chemical energy; During discharge, the hydroxide ions (OH -) in cadmium (Cd) and sodium hydroxide (NaOH) located at the negative electrode react to form cadmium hydroxide, which attaches to the anode and releases electrons, converting chemical energy into electrical energy;

3. Different charging and discharging characteristics: Lithium batteries have strict control over the charging and discharging current, which cannot be too large, and the voltage gradually decreases and changes greatly during discharge. However, lithium batteries have higher charging efficiency and no memory effect; Nickel cadmium batteries can be charged quickly with high current and provide high current to the load, with minimal voltage changes during discharge. However, their charging efficiency is low and the memory effect is severe;

4. Different single cell voltages: lithium batteries have a single cell voltage of 3.6V or 3.7V, while nickel cadmium batteries have a single cell voltage of 1.2V;

5. Different durability characteristics: Lithium batteries are more delicate, and over discharge or over charge can cause permanent damage, so a protective circuit board needs to be installed, and they need to be charged and discharged for maintenance after about six months; Nickel cadmium batteries are resistant to overcharging or overdischarging, easy to operate, and will not deteriorate performance even after prolonged storage. They can restore their original characteristics after being fully charged;

6. Different power capacity ratios: Lithium batteries have a higher power capacity and can store more electricity than nickel cadmium batteries with the same weight and volume;

7. Different environmental characteristics: Cadmium in nickel cadmium batteries is toxic, so nickel cadmium batteries are not conducive to the protection of the ecological environment. Many disadvantages have made nickel cadmium batteries basically eliminated from the application range of digital device batteries. Lithium batteries, on the other hand, do not contain toxic elements and have minimal environmental impact, making them widely used in digital electronic devices.