According to the different electrolyte materials used in lithium ion batteries, lithium ion batteries can be divided into two categories: liquid lithium ion batteries (lithium ion battery, abbreviated as LIB) and polymer lithium ion batteries (polymer lithium ion battery, abbreviated as LIP).
The positive and negative materials used in liquid lithium ion batteries and polymer lithium ion batteries are the same as liquid lithium ion, and the working principle of the batteries is also basically the same. Generally, LiCoO2 is used for the positive electrode and various carbon materials such as graphite for the negative electrode, while aluminum and copper are used as the collector fluid.
The main difference between them is the electrolyte, Li-ion batteries use liquid electrolyte, while polymer Li-ion batteries use polymer electrolyte instead, which can be “dry” or “colloidal”. Most of them use polymeric colloidal electrolytes.
Since the polymer lithium-ion battery uses a colloidal electrolyte that does not leak like liquid electrolyte, it is easy to assemble, making the overall battery very light and thin. Therefore, the battery shell can be made of aluminum-plastic composite film, which can increase the specific capacity of the whole battery; polymer lithium-ion battery can also be used as the cathode material, and its mass-to-energy ratio will be increased by more than 50% compared with the current liquid lithium-ion battery. In addition, polymer lithium-ion batteries have improved operating voltage and charge/discharge cycle life compared with liquid lithium-ion batteries. Based on the above advantages, polymer lithium-ion batteries are regarded as the next generation of lithium-ion batteries.