A porous Li 4 SiO 4 ceramic separator for lithium-ion batteries

Using diatomite and lithium carbonate as raw materials, a porous Li 4 SiO 4 ceramic separator is prepared by sintering. The separator has an abundant and uniform three-dimensional pore structure, excellent electrolyte wettability, and thermal stability. Lithium ions are migrated through the electrolyte and uniformly distributed in the three-dimensional pores of the separator. The sintering temperature has an important influence on the composition of the ceramic separator. When the sintering temperature reaches 650 °C, pure Li 4 SiO 4 is synthesized. The large porosity and excellent electrolyte affinity provide a maximum ionic conductivity of 1.18 mS cm -1 for the LSCS650 ceramic separator. After 120 charge-discharge cycles, the lithium iron phosphate battery assembled with the LSCS650 separator has a discharge specific capacity of 128.4 mA h g -1 and a capacity retention rate of nearly 100% at a current density of 1 C. Meanwhile, at a high current density of 10 C, the cell still has a discharge capacity of 71.4 mA h g -1 . Therefore, the Li 4 SiO 4 ceramic separator has a good application prospect in high-power lithium-ion batteries.