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What is the difference between polymer lithium battery and ternary lithium

2022-04-20


1. Materials

In terms of materials used, the positive electrode materials of polymer lithium ion batteries are divided into lithium cobalt oxide, lithium manganate, ternary materials and lithium iron phosphate materials. The negative electrode is graphite, and the working principle of the battery is basically the same. The important difference between the positive electrode materials of polymer lithium ion batteries lies in the difference of electrolytes. Liquid lithium ion batteries use liquid electrolytes, and polymer lithium ion batteries use solid polymer electrolytes instead. This polymer can be dry or glued. At present, most of the polymer gel electrolytes are used.

The positive electrode material of the ternary lithium battery uses the lithium ion battery of the ternary positive electrode material of nickel cobalt lithium manganate or lithium nickel cobalt aluminate. The ternary composite positive electrode material is made of nickel salt, cobalt salt and manganese salt as raw materials. The proportion of manganese can be adjusted according to the actual situation. The battery with ternary material as the positive electrode has high safety relative to the lithium cobalt oxide battery, but the voltage is too low.

Among them, lithium iron phosphate as a positive electrode material has a long charge-discharge cycle life, but its disadvantages are that there are large gaps in energy density, high and low temperature performance, and charge-discharge rate characteristics, and the production cost is high. Lithium iron phosphate battery technology and application The bottleneck of development has been encountered; lithium manganate batteries have low energy density, poor cycle stability and storage performance at high temperatures, so lithium manganate is only used as a cathode material for the first generation of international power lithium batteries; The dual advantages of performance and cost have been increasingly concerned and recognized by the industry, and gradually surpassed lithium iron phosphate and lithium manganate to become the mainstream technical route.

2. Performance

Performance characteristics of polymer lithium batteries: more flexible design, higher mass specific energy, wider electrochemical stability window, higher safety and reliability, longer cycle life, slower capacity decay rate, higher volume utilization rate, higher internal resistance Small, light weight, less self-discharge.

Performance characteristics of ternary lithium batteries: In terms of safety, it is safer than lithium cobalt oxide batteries, but lower than lithium iron phosphate batteries. The safety of all current commercial lithium ion batteries is at a medium level, and it still needs to be improved; In terms of energy density, it far exceeds lithium cobalt oxide batteries, lithium manganate batteries and lithium iron phosphate batteries; on the voltage platform, its monomer has an absolute advantage, which is 3.7V, while lithium iron phosphate is 3.2V, and lithium titanate is 2.3V. V.