Effect of heat treatment temperature on electrochemical properties of organic silane microspheres

Abstract

• The increase of temperature is conducive to the conductive network of carbon. • High temperature can improve the first coulombic efficiency of the material. • At a current density of 500 mA·g −1 , the specific capacity was 678.44 mAh·g −1 . Nano-SiO X (X ∼ 2.74) doped carbon composites were synthesized by simple co-condensation in Stöber waters and subsequent heat treatment, and the heat treatment process was studied. In the composites, carbon and silicon oxide are closely bonded. The doped carbon can provide continuous network to drop the specific resistance of the composites, to buffer volume effect of lithium embedding, so as to prevent the active substances from stripping from the collecting fluid. Higher heat treatment temperature reduces specific surface area of electrode materials, enhances the first charge-discharge capacity retention rate of the material, promotes the removal of carbon and oxygen elements, and improves the specific capacity of the material. After 100 cycles at 0.5 A·g −1 current density, the charge specific capacity was 678.44 mAh·g −1 . The composite provides excellent chemical properties, which makes it qualified to be an electrode composite for lithium-ion batteries.