The main reason is that the electrolytes are different: due to the safety problems of lithium-ion batteries, most of them now use polymer batteries, and the shape of polymer batteries can be cut into any what form.
Lithium-ion batteries mainly use liquid electrolytes and their solvents are anhydrous organic substances such as EC (ethyl carbonate), PC (propylene carbonate), DMC (carbonate of dimethyl), DEC (diethyl carbonate) and most. use mixed solvents, such as EC2DMC and PC2DMC, etc. Conductive salts include LiClO4, LiPF6, LiBF6, LiA sF6 and LiOSO2CF3. Their conductivities are in the order LiAsF6 > LiPF6 > LiClO4 > LiBF6 > LiOSO 2CF3. LiClO4 is prone to explosions and other safety issues due to its highly oxidizing property.
Polymer electrolytes can generally be divided into pol electrolytesdry solid ymers (SPE) and gel polymer electrolytes (GPE). SPE solid polymer electrolytes are primarily based on polyethylene oxide (PEO).