Structure, Stoichiometry, and Electrochemical Performance of Li₂CoTi₃O₈ as an Anode Material for Lithium‐Ion Batteries

Abstract

Li2CoTi3O8 powder has been synthesized by a simple citric nitrate method and was evaluated as an anode material for lithium‐ion batteries. The X‐ray diffraction (XRD) Rietveld refinement and X‐ray photoelectron spectroscopy (XPS) measurements indicate the existence of Ti‐site deficiency and a mixed‐valence state of Co ions in the Li2CoTi3O8 structure. The refined site‐occupation result gave a nonstoichiometric chemical formula of Li2CoTi2.682O8, which corresponds to a theoretical specific capacity of 322 mA h g−1, which is much higher than that of the stoichiometric material (233 mA h g−1). The synthesized Li2CoTi2.682O8 material exhibits high reversible capacity (ca. 320 mA h g−1), and excellent cycling stability and rate capability. A specific capacity of about 240 and 160 mA h g−1 can be achieved at 2 and 6 A g−1, respectively, by the Li2CoTi2.682O8 material. First‐principles calculation demonstrates that Ti‐site deficiency decreases the bandgap and thus facilitates the electron conduction.

Advanced electrochemical investigations of niobium modified Li2ZnTi3O8 lithium ion battery anode materials

“…This for example match hkl (211), hkl (12-2), zone axis [-453], (h) lattice 1 = 5.7 Å, lattice 2 = 4.6 Å, angle = 90 degree. This for example match hkl (110), hkl (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11), zone axis [1-1-2], (i) lattice 1 = 3.5 Å, lattice 2 = 3.3 Å, angle = 78 degree. This for example match hkl (211), hkl (11-2), zone axis [-351].…”

“…Researchers are interested in developing new anode materials for lithium ion batteries due to the increased demand of energy density and power density for lithium ion batteries. Recently a titanium containing class of compounds Li2MTi3O8 (M= Ni, Zn, Mg, Co) attracted attention due to its higher theoretical capacity and stability [5,7,8]. Introduction of Zn in the cubic spinel type structure (Li2ZnTi3O8) results in a two-step discharge process with voltage plateaus at ~1V and ~ 0.5V and a charge plateau at ~1.5V.…”

Comparison of different methods for Li2MTi3O8 (M – Co, Cu, Zn) synthesis

“…A similar method of transforming Ti(C 4 H 9 O) 4 into a citrate form with the introduction of Co and Li nitrates into the reaction mixture, as well as citric acid (C 6 H 8 O 7 ; as a chelating agent), followed by evaporation and ignition of a mixture heated to 250 °C, was used to synthesize Li 2 CoTi 3 O 8. 22 …”

Synthesis of Co-lean and Co-rich Li2CoTi3O8-based pigments: Potential Co reduction and blue-green dichroism

“…Recently, Li 2 CoTi 3 O 8 is also studied as an anode material for lithium ion batteries due to its high specific lithium storage capacity and high electronic conductivity [14][15][16]. Li…”