An inorganic membrane as a separator for lithium-ion battery

Abstract An Al 2 O 3 inorganic separator is prepared by a double sintering process. The Al 2 O 3 separator has a high porosity and good mechanical strength. After the liquid electrolyte is infiltrated, the separator exhibits quite high ionic conductivities, and even the conductivity reaches 0.78 mS cm −1 at −20 °C. Furthermore, the inorganic separator has an advantage over the polymer separator in the electrolyte retention. The LiFePO 4 /graphite cell using the Al 2 O 3 inorganic separator shows higher discharge capacity and rate capability, and better low-temperature performance than that using the commercial polymer separator, which indicates that the Al 2 O 3 separator is very promising to be applied in the lithium-ion batteries.