Synthesis of LiTi2(PO4)3-acetylene black nanocomposites for lithium ion batteries by the polyvinyl alcohol assisted sol–gel method and ball-milling

Lithium titanium phosphate (LiTi2(PO4)3) has been successfully synthesized by a polyvinyl alcohol (PVA) assisted sol–gel method. To further improve its electrochemical properties, a ball-milling process with various amount of acetylene black (AB) has been used to form LiTi2(PO4)3-AB nanocomposites (the weight ratio of acetylene black is 5wt.%, 10wt.%, 15wt.% and 20wt.%). The samples are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Electrochemical performance of the samples is characterized by the charge–discharge test, cyclic voltammetry (CV), electrochemical impedance spectroscopic studies (EIS), and galvanostatic intermittent titration technique (GITT). The results show that the ball-milling process enables LiTi2(PO4)3 nanoparticles to network with conductive acetylene black, which offers better electrochemical performance. Especially, LiTi2(PO4)3-AB nanocomposite with 15wt.% acetylene black shows the best electrochemical properties, which delivers the highest specific capacity and the best cycle performance. Besides, the thermodynamics properties of as-prepared samples are also been studied. ► LiTi2(PO4)3 can be synthesized by PVA sol–gel method at a low temperature successfully. ► LiTi2(PO4)3-acetylene black nanocomposites was synthesized by a simple ball-milling. ► LiTi2(PO4)3- acetylene black nanocomposite with 15wt.% acetylene black shows excellent electrochemical properties.