Selective Synthesis of Lithium Ion‐Conductive β‐LiVOPO₄ Crystals via Glass–Ceramic Processing

Abstract

A glass-ceramic processing is applied to a glass with the composition of 33.3Li 2 O-33.3V 2 O 5 -33.3P 2 O 5 (mol%) in order to synthesize lithium ion-conductive b-LiVOPO 4 crystals being a potential candidate for cathode materials in lithium ion batteries. It is found that three crystalline phases of a-LiVOPO 4 , Li 2 VPO 6 , and b-LiVOPO 4 are formed during the crystallization and a-LiVOPO 4 crystals formed initially transform into b-LiVOPO 4 . The glass-ceramics consisting of almost mainly b-LiVOPO 4 crystals are successfully prepared by a heat treatment at around 6001C in air. The glass-ceramics with b-LiVOPO 4 crystals show the electrical conductivity of 1.7 Â 10 À7 S/cm at room temperature and the activation energy of 0.38 eV in the temperature range of 251-2401C. The structure and electrical properties of the precursor glass are also examined. The present study proposes that the glass-ceramic processing has an advantage for the fabrication of b-LiVOPO 4 crystals, because it is difficult to synthesize b-LiVOPO 4 crystals using a conventional powder-sintering method.

Hollow α-LiVOPO4 sphere cathodes for high energy Li-ion battery application

“…No other common impurities such as Li 3 PO 4 , Li 2 VPO 6 and V 2 O 5 have been observed. 18,29 Several control try-outs have been conducted to establish the factors that govern the formation of hollow a-LiVOPO 4 microspheres including effects of (1) temperature, (2) time, (3) precursor and (4) solvent. when the reaction duration has reached at 20 h (Fig.…”

“…Besides this, the high temperature a-LiVOPO 4 phase has more open framework with large Li sites in which Li atoms are loosely bound as compared to the metastable b-LiVOPO 4 . 26 Till now LiVOPO 4 has been synthesised by high temperature ceramic routes, 16,[27][28][29] hydrothermal methods 18,26 or combination of these methods to synthesize VOPO 4 followed by lithiation to produce LiVOPO 4 . 16,17 However, these methods suffer from the unavoidable high-energy utilization and polydispersed growth of the grains due to the high processing temperatures (generally at 600-900 C) which also increase the material cost.…”

Fabrication of LiFePO4/carbon composites by glass powder crystallization processing and their battery performance

“…Crystallization of glass is a method for fabrication of dense condensed materials with desired shapes and also nanostructures [12][13][14]. Nagamine et al [15,16] also applied the glass crystallization method to the syntheses of Li 3 Fe 2 (PO 4 ) 3 and β-LiVOPO 4 ceramics. Thokchom and Kumar [17] reported lithium ion conductive glass-ceramics consisting of Li 1+x Al x Ti 2−x (PO 4 ) 3 in the system of Li 2 O-Al 2 O 3 -TiO 2 -P 2 O 5 , and recently Pang et al [18] tried to pattern crystal lines of Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 on the glass surface by a laser irradiation technique.…”

Enhanced electrochemical performance of manganese-doped β-LiVOPO4 cathode materials for lithium-ion batteries

“…LiVOPO 4 has different crystallographic phases such as tetragonal α-LiVOPO 4 [7,8] and orthorhombic β-LiVOPO 4 [6,[9][10][11], and it has been reported that β-LiVOPO 4 exhibits excellent electrochemical performances as lithium-ion batteries [6].…”