Through comparison, it can be found that lithium-ion batteries mainly have the following advantages.
(1) The working voltage is high. The operating voltage of single lithium-ion battery is as high as 3.6V, which is 3 times that of nickel-cadmium and nickel-hydrogen batteries, and 2 times that of lead-acid batteries.
(2) The energy density is large. Lithium-ion batteries have a high working voltage, and lithium is the metal with the smallest density. Therefore, the volume and weight energy density of lithium-ion batteries are relatively large. Generally, the weight energy density is twice that of nickel-hydrogen batteries and four times that of lead-acid batteries; The volumetric energy density is 2-3 times that of lead-acid batteries, making it lighter and more portable.
(3) Low self-discharge rate. Self-discharge refers to the phenomenon that the internal spontaneous reaction of the battery causes the capacity of the battery to decrease when the battery is not connected to an external circuit. The self-discharge rate of lithium-ion batteries is much lower than that of nickel-cadmium and nickel-metal hydride batteries, and it is easier to store.
(4) Long cycle life. Lithium-ion batteries are based on the intercalation-extraction reaction mechanism. Theoretically, the structure of the positive and negative electrodes during the charge and discharge process does not change, and the reaction is reversible. In practical applications, the cycle can reach more than 1,000 times, can be used for a long time, has high resource utilization, and is economical.
(5) No memory effect. Lithium-ion batteries can be charged and discharged at any time, and there will be no reduction in capacity caused by the memory effect like nickel-cadmium and nickel-metal hydride batteries.
In addition, the lithium-ion battery has a wide operating temperature range (-20~60℃) and does not contain heavy metal elements such as cadmium, lead, mercury, etc., making it an ideal "green" environmentally friendly chemical power source.
However, lithium-ion batteries also have some problems that cannot be ignored. The most prominent is the safety problem, which is caused by its high specific energy and poor material stability; in addition, the lack of lithium resources and the high production price, the same voltage and the same The price of a capacity lithium-ion battery is 3-4 times that of a lead-acid battery, which limits its application in large-scale smart grid technology.