Analysis of advantages and disadvantages of four power lithium battery technology routes

According to different technical routes, solid-state batteries are mainly divided into polymer all solid-state batteries, oxide all solid-state batteries and sulfide all solid-state batteries.
All solid state polymer battery was first studied in 1973; Oxygenate all solid state battery is earlier, which was studied in 1953; The sulfur compound all solid state battery was first studied in 1981.
The main advantages of polymer all solid state battery: it is easy to process, can prepare large capacity cells, has soft mechanical properties, has similar properties with the electrolyte currently used, and the process is relatively close to the current lithium battery. It is the most easy to use the existing equipment to realize mass production through transformation.
The main disadvantage of polymer all solid state battery: the ionic conductivity is the lowest, which must be heated to more than 60 degrees before the ionic conductivity can be improved, close to 10-3 s / cm, so it is necessary to maintain a high temperature state. The energy density is limited. Because the polymer is organic and has poor electrochemical performance, it is not as good as other solid-state inorganic solid-state battery materials. It has good compatibility with lithium iron phosphate and poor compatibility with ternary, resulting in the inability to improve the energy density.
Main advantages of oxygenate all solid state battery: withstand high voltage and higher conductivity than polymer. The ionic conductivity of oxide can reach the level of 10-5-3 s / cm, but it is not as good as that of liquid electrolyte. Typical examples include oxides such as LAGP and LATP.
The main disadvantages of oxygenate all solid state battery: the mechanical properties of oxide are hard. If it is used to make electrolyte sheet, it is easy to break; The solid-solid contact with the positive active material is not good enough, resulting in the change from surface contact to point contact, and the interface loss is too large; The above disadvantages make it difficult to prepare high-capacity cells. Now the oxide can only be compounded with electrolyte or polymer to make the solid-liquid hybrid battery used now, so as to reduce the content of electrolyte.
The main advantages of sulfur compound all solid state battery: good contact, so the overall ionic conductivity is very good, the particles are relatively soft, and the solid-solid contact is easy to form surface contact. It is the only material that can exceed the ionic conductivity level of liquid electrolyte in all solid state battery materials, and it is also the most possible technical route of all solid state battery in the future.
The main advantages of sulfur compound all solid state battery: the product cost is very high and the air stability is poor. Sulfide has strong chemical activity and strong reaction with air, organic solvents and positive and negative active materials. Therefore, the interface stability is poor, resulting in difficulties in production, transportation and processing, which limits its wide application.