High-performance LiTi 2 (PO 4 ) 3 @carbon anode using double carbon sources for aqueous lithium ion battery

Abstract

Abstract In this paper, LiTi 2 (PO 4 ) 3 @carbon composite as anode for aqueous lithium ion battery has been successfully synthesized by in-situ carbon coating method using oxalic acid and glucose as double carbon sources. XRD results confirm the rhombohedral NASICON-type LiTi 2 (PO 4 ) 3 structure of the as-prepared composite. The LiTi 2 (PO 4 ) 3 @carbon composite using double carbon sources (LTP-OG-10) disperses well, and the coated carbon layer has the appropriate thickness of 3–7 nm, which result in proper balance of the good electrical conductivity and the fast kinetics of diffusion of lithium ions. LTP-OG-10 exhibits better electrochemical performance compared with those using oxalic acid (LTP-O) or glucose (LTP-G) single carbon source. LTP-OG-10 anode delivers the discharge capacity of 112.5 mA h g −1 , 96.8 mA h g −1 , and 54.2 mA h g −1 at 0.2 C, 5 C and 20 C, respectively, much larger than that of LTP-O and LTP-G. Moreover, LTP-OG-10 demonstrated excellent cycling performance, with the capacity retention of 71.1% after 400 cycles at 0.2 C, 22.9% higher than that of LTP-G. The good electrochemical properties of LTP-OG-10 is mainly ascribed to the increase of defects, high-quality and appropriate thickness of carbon layer. Our study reveals that preparing LiTi 2 (PO 4 ) 3 @carbon composite using double carbon sources is an efficient approach to enhance its electrochemical properties.