Effect of Doping Ti4+ on the Structure and Performances of Li3V2(PO4)3

Synthesis and electrochemical properties of Co-doped Li3V2(PO4)3 cathode materials for lithium-ion batteries

“…The Rietveld analysis of neutron-diffraction data confirmed that this improved charge/discharge cycle performance resulted from the disordered lithium-ion arrangement in the orthorhombic phase. The enhancement of the discharge capacity and cycle performance were also observed with the substitution of Ti 4+ into vanadium sites in Li 3 V 2 (PO 4 ) 3 systems [13], where the first two plateaus in the discharge curves presented slightly sloping profiles, and the boundary gradually became ambiguous with further increases in the substitution ratio. These results show that the ionic conductivity of a Ti-doped material can be increased by up to three orders of magnitude, and the enhancement of the conductivity and specific capacity as well as the disappearance of the twoplateau boundary in the charge/discharge curves can be attributed to the disorder of lithium ions due to additional vacancies introduced into the lithium sites by the Ti 4+ doping.…”

“…In the monoclinic Li 3 V 2 (PO 4 ) 3 phase, the first charging voltage step between 3.61 V and 3.68 V is related to the presence of an ordered Li phase of intermediate composition, Li 2.5 V 2 (PO 4 ) 3 ; the second step, between 3.68 V and 4.1 V, is associated with the removal of Li ions from stable tetrahedral sites; and the final step, between 4.1 V and 4.5 V, is due to the change of the V 3+/4+ redox couple to the V 4+/5+ [6][7][8][9]. To date there are few reports relating to the investigation of the substitution behavior of Fe 3+ , Al 3+ , Zr 4+ , Ti 4+ and Cr 3+ in vanadium sites in Li 3 V 2 (PO 4 ) 3 systems [10][11][12][13][14]. All these substitutions influence the electrochemical performance of Li 3 V 2 (PO 4 ) 3 to different extents; in particular, some substitutions can enhance cycle performance but at the sacrifice of discharge specific capacity.…”

Li3V2(PO4)3/graphene nanocomposite as a high performance cathode material for lithium ion battery

“…Furthermore, LVP has low intrinsic electronic conductivity (2.4 Â 10 À 7 S cm À 1 ) [17], which greatly limits its practical application. To overcome this disadvantage and enhance the rate capability of LVP, various methods have been employed in the past few years: doping with foreign atoms [16,[18][19][20][21], decreasing the particle size [8,22] and carbon coating [23][24][25][26][27][28][29]. Carbon coating is simple and efficient for enhancing the electrical conductivity of LVP, although increased carbon content, significantly decreases the tap density and energy density of LVP [30].…”

ZrO2-coated Li3V2(PO4)3/C nanocomposite: A high-voltage cathode for rechargeable lithium-ion batteries with remarkable cycling performance

“…Although, Li 3 V 2 (PO 4 ) 3 exhibits faster lithium-ion migration rate than LiFePO 4 due to its open three-dimensional (3D) framework, the intrinsic poor electronic conductivity (2.4 Â 10 À 7 s À 1 at room temperature) critically limits its practical applications in electric vehicles (EVs) and hybrid electric vehicles (HEVs). It is generally believed that carbon coating [6,[8][9][10], and doping of other metal ions such as Mg 2 þ [11], Mn 3 þ [12], Fe 3 þ [13], Co 2 þ [14], Ti 4 þ [15], Al 3 þ [16], Zr 4 þ [17] are beneficial for improving the electrochemical performances of the pristine Li 3 V 2 (PO 4 ) 3 .…”