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

Abstract

A series of surface-doped LiMn 2 O 4 samples modified by a Li 2 CuO 2-Li 2 NiO 2 solid solution were synthesized using a simple and facile sol-gel method to achieve the enhanced cycling performance, especially at elevated temperatures. The corresponding phase structure and morphology were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The modified layer on the surface of LiMn 2 O 4 particles, featuring a LiNi δ Mn 2-δ O 4-like phase, together with a Li 2 CuO 2-Li 2 NiO 2 solid solution, as confirmed by XRD and transmission electron microscopy (TEM), plays a key role in alleviating the dissolution of manganese, thus enhancing the cycling performance and rate capability relative to bare LiMn 2 O 4. The 0.5 wt.%-modified LiMn 2 O 4 sample delivers a discharge capacity of 113 mAh g-1 and a capacity retention of 93.2% following 300 cycles at 1 C and 25 °C, which is higher than the values of 96 mAh g-1 and 81.2% for bare LiMn 2 O 4. In addition, at 55 °C, a capacity retention of 81.2% at 1 C is obtained for the 0.5 wt.%-modified LiMn 2 O 4 sample after 200 cycles, compared to 70.0% for bare LiMn 2 O 4. Modifying the surface of the latter by a LiNi δ Mn 2-δ O 4-like phase mixed with a Li 2 CuO 2-Li 2 NiO 2 solid solution, is an effective strategy for improving electrochemical properties.

Enhanced Cycling Stability through Erbium Doping of LiMn2O4 Cathode Material Synthesized by Sol-Gel Technique

“…As an optimal choice for green travel, electric vehicles with rechargeable batteries have become very popular all over the world. Meanwhile, lithium-ion batteries, as the power source, have been developed quickly in recent years [1,2,3,4,5,6,7,8]. It is generally known that there are four major classes of mature cathode materials, namely LiCoO 2 [9,10], LiFePO 4 [11,12], LiNi 1−x−y Co x M y O 2 (M = Mn, Al) [13,14], and LiMn 2 O 4 [15,16], for batteries.…”

“…Among these materials, LiMn 2 O 4 shows many virtues such as mature production technology, cheap production costs, non-pollution characteristics, and so forth [17,18,19,20]. However, the large-scale commercial applications of this material have been seriously restricted because of its poor cycling life and high-temperature performance, which are mostly a consequence of Jahn–Teller distortion, manganese dissolution, and non-uniform particle-size distribution [7,21,22,23,24]. Therefore, there is a tremendous need to optimize this material for better performance.…”

Insights into Electrochemistry and Mechanical Stability of α- and β-Li2MnP2O7 for Lithium-Ion Cathode Materials: First-Principles Comparison

“…Lithium ion batteries (LIBs), as one of the most promising candidates for chemical energy storage and conversion devices, have captured a dominant market share of the portable electronics and electric transportation in the past decades. − Because the cathode material is vital for energy storage and cost-effectiveness, tremendous efforts are devoted to design and develop next-generation cathode materials with excellent electrochemical properties. Typical examples comprise the layered LiCoO 2 , − olivine LiMPO 4 (M = Fe and Mn), − and spinel LiMn 2 O 4 . − However, under the ever-increasing usage of LIBs expanding to large-scale application, the conventional cathode materials could not meet the requirement as a consequence of cost-effectiveness or safety hazards. Therefore, searching novel cathode materials for LIBs is an integral aspect of the ongoing quest for building better batteries.…”

Room-Temperature Synthesis of LiMn2O4by Electrochemical Ion Exchange in an Aqueous Medium

“…For a better comparison, only pristine LiMn 2 O 4 electrodes without any carbon coating/composite or surface doping are reported in this table. Despite the lower capacity of the CLMO electrode fabricated by ECIE, it presents better capacity retention versus the discharge rate than some microsized or submicrosized LiMn 2 O 4 for a similar rate range. ,,,,− In some cases, CLMO presents even similar or better capacity from 4C rate. ,,,,, The CLMO electrode retains 80% of its initial capacity upon 500 cycles at a high rate of 6.8C (1 A g –1 ) and presents high Coulombic efficiency superior to 99%, indicating the high reversibility of the involved redox reactions (Figure e). Compared to other reported LiMn 2 O 4 electrodes (Table ), the electrode is generally more stable for an extended number of cycles and for a higher rate.…”

“…Generally, the CLMO electrode presents the first discharge capacity in the range between 100 and 130 mAh g –1 , but it has poor capacity retention versus high rates and long cycling, preventing its use in marketed LiB devices. Many synthesis methods, such as solid-state reaction, , sol–gel, − combustion, − and precipitation, − have been reported but all of them need a high-temperature calcination step for obtaining the crystalline phase at the end of the process, which is not energy-saving. Investigation on other energy-efficient alternative methods would be critical to remove the high-temperature calcination step.…”