Improving the electrochemical properties of lithium-ion secondary battery by the in-situ synthesis of LiCo0.91O1.84 on positive electrode

Abstract

LiCo 0.91 O 1.84 crystal is successfully in situ synthesized on Pt substrates by the molten salt method. A LiCo 0.91 O 1.84 crystal layer with a thickness of 1 μm is formed on the Pt substrate surface, and LiCo 0.91 O 1.84 nano-crystal with a cross lamellar structure grows on the surface of the crystal layer. It is proved that atomic bonding is achieved at the LiCo 0.91 O 1.84 /Pt interface. Higher reaction temperature causes the crystal losing the nanostructure and weakening the bonding strength at the LiCo 0.91 O 1.84 /Pt interface. Shorter holding time results in lower crystallinity, while longer holding time leads to poor bonding strength. Therefore, 500 °C/3h is selected as the optimum parameter for the LiCo 0.91 O 1.84 preparation. The electrochemical test results show that the in-situ grown LiCo 0.91 O 1.84 electrode has better specific capacity, cycle performance and rate performance than the powdered LiCo 0.91 O 1.84 electrode fabricated by the traditional process.