Structural Study of Electrochemically Obtained Li2+xTi3O7

On the Synthesis of Ramsdellite LiTiMO4 (M = Ti, V, Cr, Mn, Fe): An Experimental and Computational Study of the Spinel–Ramsdellite Transformation

“…The average lithium de-intercalation voltages of LiTi 2 O 4 for both ramsdellite and spinel structural types have also been computed in this work as some of them are known experimentally and their comparison may be a convenient way of validating the calculations. Since the insertion reaction is written as Equation (2) the open-circuit average voltage for the lithium insertion pro-cess can be obtained as explained by Aydinol et al [24] from a total energy difference expression [see Equation (3); E total refers to the total energy per formula unit] if entropy and volumetric effects are ignored.…”

“…The small changes in the basic ramsdellite cell parameters during the intercalation process, also known as zero-strain behavior, are likely to be the origin of the good capacity retention with cycling. [3] [9,10] On the other hand, spinels with the formula LiTiMO 4 (M = Ti, V, Cr, Mn, and Fe) are known to exist. With the aim of preparing the novel ramsdellites LiTiMO 4 (M = V, Cr, Mn, and Fe), in this work we will try to induce the spinel-ramsdellite phase transformation by thermal treatment in a reaction that can be written as:…”

“…[1,2] The presence of unoccupied Li sites in these channels in ramsdellite Li 2 Ti 3 O 7 allows for a further lithium uptake of up to 2.24 Li ions, which means that Li 2 Ti 3 O 7 would deliver a specific capacity of 240 Ah kg -1 as an electrode in a lithium cell. [3] The high temperature polymorph of spinel LiTi 2 O 4 also presents the ramsdellite structural type. Hereafter the spinel polymorph will be denoted as LiTi 2 O 4 (S) while the ramsdellite polymorph will be denoted as LiTi 2 O 4 (R).…”

Solvothermal synthesis and electrochemical characterization of amorphous lithium titanate materials

“…For the anode, diversiform of carbon materials were used, from low-temperature carbon with amorphous structure to well-crystallized natural graphite and also carbon nanotubes. In addition to these carbon materials, lithium titanium oxides, for example Li 4 Ti 5 O 12 [1,2] and Li 2 Ti 3 O 7 [3,4], in the form of amorphous or crystalline, were also proposed to be used for anode. They offer a theoretical capacity of 175 and 240 mAh/g, respectively, stable operating voltage of approximately 1.5 V versus lithium, and good reversibility in the charge-discharge * Corresponding author.…”

High temperature electrochemical behaviors of ramsdellite Li2Ti3O7 and its Fe-doped derivatives for lithium ion batteries

“…At present, the investigations as anode materials are mainly concentrated on spinel, Li 4 Ti 5 O 12 , ramsdellite, Li 2 Ti 3 O 7 , and their related solid solutions due to their lower voltage [2][3][4][5][6][7][8][9][10][11][12]. Research works for electrochemical cell performance of Li 2 Ti 3 O 7 have been carried out at room temperature with focus on the preparation, structure characterization and electrochemical cell performance, and it was believed that this host structure is stable during charge/discharge cycles at usual environmental temperatures [3][4][5]10,11]. Applications exposed to the temperatures of higher than 50 • C are common in tropical area, especially for appliances with poor ventilation cooling like electric vehicle.…”