Compared with other high-energy secondary batteries such as nickel-cadmium batteries, nickel-hydrogen batteries, lead-acid batteries, etc., lithium-ion batteries have significant advantages in performance, which are mainly reflected in the following aspects.

1. High working voltage

Using carbonaceous lithium intercalation compounds such as graphite or petroleum coke instead of metallic lithium as the negative electrode reduces the battery voltage. However, due to their low lithium intercalation potential, voltage losses can be minimized. At the same time, selecting a suitable lithium intercalation compound as the positive electrode of the battery and selecting a suitable electrolyte system (determining the electrochemical window of the lithium-ion battery pack) can make the lithium-ion battery pack have a higher working voltage (-4V), much higher than Water battery.

2. Large capacity

Although the use of carbonaceous materials to replace metal lithium will reduce the mass specific capacity of the material, in fact, in order to ensure a certain cycle life of metal lithium secondary batteries, the negative metal lithium usually exceeds the standard by more than three times. The actual decrease in mass specific capacity is not large, and the decrease in volume specific capacity is very small.

3. High energy density

Higher operating voltage and volumetric capacity determine the higher energy density of secondary lithium-ion batteries. Compared with the widely used nickel-cadmium batteries and nickel-hydrogen batteries, secondary lithium-ion batteries have the highest energy density and still have great development potential.

4. Good safety performance and long cycle life

Batteries that use metallic lithium as the negative electrode are unsafe because the structure of the positive electrode of the lithium-ion battery changes, forming porous dendrites. It can pierce the separator and cause an internal short circuit, whereas lithium-ion batteries do not have this problem and are very safe. To prevent the presence of metallic lithium in the battery, the voltage should be controlled during charging. To be on the safe side, lithium-ion batteries are equipped with multiple safety devices. Li-ion batteries do not have any structural changes in the intercalation and deintercalation of lithium ions on the positive and negative electrodes during the charging and discharging process (the lattice will expand and contract to a certain extent during the intercalation and deintercalation process), and since the intercalation compound is more efficient than the metal Lithium is more stable and does not form lithium dendrites during charging and discharging, thereby significantly improving the safety performance of the battery and greatly improving the cycle life. Lithium-ion batteries were excluded as dangerous goods by the U.S. Department of Transportation's Division of Dangerous Goods Transportation and the IAIT (International Air Transport Association) in 1989 and 1990, respectively.

5. Low self-discharge rate

Lithium-ion batteries use a non-aqueous electrolyte system, and lithium-intercalating carbon materials are thermodynamically unstable in the non-aqueous electrolyte system. During the first charge-discharge process, due to the reduction effect of the electrolyte, a solid electrolyte interface (SEI) film will be formed on the surface of the carbon negative electrode, allowing lithium ions to pass through but not electrons, allowing materials with different charge states of electrode activity to pass through. In a relatively stable state, it has a low self-discharge rate.

6. Clean and pollution-free

Lithium-ion battery packs do not contain toxic substances such as lead, mercury, and mercury. At the same time, since the battery must be well sealed, very little gas is released during use and will not pollute the environment. The solvent used to dissolve the binder during the manufacturing process can also be fully recovered. Large-scale lithium-ion battery manufacturers such as Sony have been recycling lithium-ion batteries and materials (such as metal drills) since 1997. In addition, in 1996, Sony's lithium-ion batteries were certified to comply with the IS014001 international environmental standard.

7. High current efficiency

Unlike any previous water-based secondary batteries, lithium-ion batteries do not generate gas during normal charging and discharging, and the current efficiency is close to 100%. This characteristic is particularly suitable for use as batteries for power storage and conversion.