Improved electrochemical properties of LiMn₂O₄ with the Bi and La co-doping for lithium-ion batteries

Abstract

A series of LiBi x La x Mn 2-2x O 4 (x=0, 0.002, 0.005, 0.010, 0.020) samples were synthesized by solution combustion synthesis in combination with calcination. The phase structure and morphology of the products were characterized by X-ray diffraction, scanning electron microscopy, and transition electron microscopy. The results demonstrated that a single-phase LiMn 2 O 4 spinel structure was obtained for the LiBi x La x Mn 2-2x O 4 (x=0, 0.002, 0.005) samples, whereas impurities were observed for the LiBi x La x Mn 2-2x O 4 (x=0.010, 0.020) samples as a result of the doping limit. The electrochemical properties were investigated by galvanostatic charge-discharge cycling and cycling voltammetry in a voltage range of 3.2-4.4 V. The substitution of Mn 3+ by equimolar Bi 3+ and La 3+ could significantly improve the structural stability and suppress the Jahn-Teller distortion, thereby resulting in improved electrochemical properties for the Bi and La co-doped samples in contrast with the pristine LiMn 2 O 4 sample.In particular, the LiBi 0.005 La 0.005 Mn 1.99 O 4 sample delivered a high initial discharge capacity of 130.2 mAh/g at 1 C, and following 80 cycles, the capacity retention was as high as 95.0%. Moreover, it also presented the best rate capability among all the samples, in which a high discharge capacity of 98.3 mAh/g was still maintained at a high rate of 7 C compared with that of 75.8 mAh/g for the pristine LiMn 2 O 4 sample.

Improved electrochemical performance of LiMn2O4 surface-modified by a Mn4+-rich phase for rechargeable lithium-ion batteries

“…LiMn2O4 powders were prepared by solution combustion synthesis (SCS) in combination with calcination [17,29,30]. Lithium nitrate (LiNO3, 99.0%, Kishida Chemical Co., Ltd., Japan), lithium acetate (CH3COOLi, 99.0%, Kishida Chemical Co., Ltd., Japan), manganese nitrate (Mn(NO3)2, 50% w/w aqueous solution, Alfa Aesar), and urea (NH2CONH2, 99.0%, Chameleon Reagent, Japan) were used as the raw materials without further purification.…”

“…Single-doping of Ni 2+ [9], Al 3+ [10], Cr 3+ [11], Sm 3+ [12], Ru 4+ [13] has been reported. Co-doping with Ni-Cu [14], Cr-Fe [15], Mg-Si [16], and La-Bi [17] has also been carried out. The results have shown that these doped LiMn2O4 spinel materials display enhanced stabilization of their structure and improved cycling performance compared with nondoped LiMn2O4 materials.…”

Enhanced cycling performance of surface-doped LiMn2O4 modified by a Li2CuO2-Li2NiO2 solid solution for rechargeable lithium-ion batteries

“…and La-Bi [14], has been carried out to retard capacity fading, the irreversible capacity loss arising from the dissolution of manganese cannot be completely alleviated both at room and elevated temperatures [15]. Surface modification, being another effective approach, is drawing more interest, since it can give rise to improved electrochemical properties due to its protective effect at the cathode/electrolyte interfaces, not only suppressing the dissolution of manganese, but also improving operation safety and structural stability [16,17].…”

Enhancement of battery performance of LiMn2O4: correlations between electrochemical and magnetic properties

“…[9][10][11] So far, many substitutions (S, F, Br, Si, B, Mg, Al, Bi, Cu, Ni, Ru, Ga, Ag, etc. [12][13][14][15][16][17][18][19][20][21][22][23][24] ) have been studied to increase the cycle life of LiMn 2 O 4 cathode. The main idea behind this approach is to suppress the Jahn-Teller distortion via increasing the valance state of Mn ions and to stabilize the spinel structure during cycling.…”

“…These studies can be classied in two categories; Lithium Boron Oxide (LBO) coated on the LiMn 2 O 4 and direct doping of B in Mn sites of LiMn 2 O 4 . [12][13][14][15][16][17][18][19][20][21][22][23][24][25]45 48 In this work, we examined the effects of B doping on the structural, magnetic and electrochemical properties of LiMn 2 O 4 . We found that the cell parameters and the cell volume increases with increasing B content.…”