Improvement of the high-rate discharge capability of phosphate-doped spinel LiMn2O4 by a hydrothermal method

Synthesis and electrochemical performance of modified LiMn2O4 by Zn2+ and PO43− co-substitution

“…The O content was calculated based on the ICP-AES data and the average Mn valence. It can be seen that the ratio of Li/Zn/Mn/P determined by ICP-AES is close to the theoretical value and the lattice parameter of undoped LiMn 2 O 4 is larger than that of any of doped [13]. It can also be seen from Table 1 that the doping increases slightly the average Mn valence.…”

“…It was reported that the cycle performance of the Zn-doped LiMn 2 O 4 sample (LiZn 0.05 Mn 1.95 O 4 ) was significantly improved and the capacity loss of LiZn 0.05 Mn 1.95 O 4 sample was less than 6% of its initial capacity after 30 cycles [12]. Ye et al [13] reported that the phosphate-doped LiMn 2 O 4 cathode (with a molar ratio of PO 4 3− :LiMn 2 O 4 = 1.5%) exhibits good high-rate discharge capability with 94 mAh·g −1 at a current density of 2960 mA·g −1 . The analysis demonstrates that the phosphate-doped samples have a relatively large Li-ion diffusion coefficient and smaller charge-transfer resistance compared with the pristine LiMn 2 O 4 sample.…”

Electrochemical performance of rare-earth doped LiMn2O4 spinel cathode materials for Li-ion rechargeable battery

“…It can be seen that all plots consist of both a semicircle in the high middle frequency and a straight sloping line in the low frequency. The semicircle at high frequency is corresponding to a charge transfer step (R ct ), which may be ascribed to the charge transfer of lithium ion on the surface of spinel oxide because there are no other electrode reactions taking place during lithium insertion and removal in the oxide, and the electrode reaction process is mainly controlled by charge-transfer process [30]. The straight line at the low frequency is Warburg impedance (W o ), which is caused by the solid-phase diffusion in the electrode materials.…”

Chemical syntheses of nanocrystalline lithium manganese oxide spinel

“…This is accompanied with evolution of large amounts of gases what prevents particles from agglomeration. Lately, hydrothermal synthesis using conventional heating [20], and microwave heating [2,21], is gaining much importance due to ease in controlling the chemical composition, crystal size and particle morphology. Unfortunately, the classical hydrothermal process is very time consuming due to slow reaction kinetics.…”