BULLETIN OF THE CHEMICAL SOCIETY OF ETHIOPIA
·
2024
·Vol. 38
·期 5
·1429-1437
·
IF 1.3
Yu Sun,Chaofan Li,Hongcheng Gao,Jiaming Li,Jiabin Hao
A cubic spinel LiMn2O4 cathode material with nanoscale was synthesized via a facile liquid-combustion method at 600, 750 and 850 ℃. The crystal structure and surface morphology of LiMn2O4 electrodes have been characterized by using X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) technique. The samples have an average diameter of 200 nm with an octahedral structure with high crystallinity. Benefiting from the excellent structure, the sample prepared at 750 ℃ delivers the highest first discharge capacity of 115.3 mAh·g−1 with remaining 101.5 mAh·g−1 after 400 cycles at 1 C. Moreover, it exhibits a good cycling performance at 55 ℃, still had the capacity of 105.4 mAh·g−1 with a capacity retention of 71.2% following 282 cycles. The facilely synthesized octahedral LiMn2O4 provides a practical application strategy for lithium-ion batteries.
KEY WORDS: Spinel LiMn2O4, Liquid-combustion method, Lithium-ion batteries
Bull. Chem. Soc. Ethiop. 2024, 38(5), 1429-1437.
DOI: https://dx.doi.org/10.4314/bcse.v38i5.18
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2022
·
IF 9.794
Yang Tao,Qing Liu,Yujiao Guo,Mingwu Xiang,Xiaofang Liu,Wei Bai,Junming Guo,Shulei Chou
Electrochemical properties of spinel LiMn 2 O 4 cathode material have been always suffered from Mn dissolution and Jahn-Teller distortion. Herein, various Ni/B dual-doped LiNi 0.08 B x Mn 1.92- x O 4 ( x = 0–0.15) with a truncated octahedral morphology are synthesized via a facile solid-state combustion. The effects of Ni/B co-doping on the morphology, crystal structure, Mn dissolution, Li + diffusion coefficient and activation energy are investigated. Due to the relatively high Ni–O and B–O bond energy than that of Mn–O bond, the structure stability of the LiMn 2 O 4 is enhanced, whilst restraining the Jahn-Teller distortion. The LiNi 0.08 Mn 1.92 O 4 shows (111), (110) and (100) facets. In comparison, the B-doping endows the LiNi 0.08 B x Mn 1.92- x O 4 ( x ≥ 0.02) with (111) and (100) facets. This morphology evolution without (110) facets effectively inhibits the Mn dissolution. Owing to the synergistic merits of Ni/B dual-doping and unique truncated octahedron , the optimized LiNi 0.08 B 0.06 Mn 1.86 O 4 delivers an initial discharge capacity of 113.9 mAh∙g −1 at 1C and maintains a durable cycling life up to 2000 cycles at 5C. Even at 20C, a capacity retention of 86.3% is still obtained after 2000 cycles. Furthermore, a capacity retention of 70.6% can be retained after 500 cycles at 5C and 55 °C. The truncated octahedral LiNi 0.08 B x Mn 1.92- x O 4 with excellent electrochemical performance will be a good candidate for developing long-life lithium-ion batteries.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Yujiao Guo,Yue Yu,Ping Ning,Jiangzhao Chen
Spinel LiMn 2 O 4 has the potential to be used as a cathode material in lithium-ion batteries because of its affordability, low toxicity, and excellent charge/discharge capability. However, severe capacity attenuation results from the degradation of its long-cycle and high-rate performance caused by the Jahn-Teller distortion and Mn dissolution. Herein, a simple solid-state combustion process is used to successfully prepare the Mg 2+ -Al 3+ co-doped LiMn 2 O 4 with truncated octahedral morphology. The Jahn-Teller distortion is inhibited by the stable Mn-O framework and the decreased lattice constant, which in turn lowers the dissolution of Mn. Moreover, Mg 2+ -Al 3+ co-doped LiMn 2 O 4 have lower activation energy and greater Li + diffusion coefficient. As a result, the optimized LiMg 0.03 Al 0.10 Mn 1.87 O 4 delivers satisfied initial capacity of 102.1 mAh‧g −1 with a capacity retention of 76.2 % after 1000 cycles at 10 C. Even at the ultra-high rate of 15 C and 20 C, Mg 2+ -Al 3+ co-doped sample also remain desired structure stability and cycling performance, which remains 73.8 % of its original capacity after 1000 cycles at 20 C. This work provides a reference for developing high-performance and stability cathode materials for lithium-ion battery.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2021
·Vol. 45
·期 35
·16101-16111
·
IF 3.591
Changwei Su,Ruifang Chen,Zhaoyao Sa,Hong Li,Mingwu Xiang,Junming Guo,Wei Bai,Xiaofang Liu
A simple and rapid microwave-induced solution flameless combustion method to prepare high-capacity Ni–Cu co-doped spinel LiMn2O4 is provided in this work. Ni–Cu co-doping effectively reduces the lattice parameters and Jahn–Teller effect of the spinel LiMn2O4 to obtain a more stable crystal structure. The microscopic morphological characteristics clarify that the growth and development of grains is significantly controlled by microwave treatment and Ni–Cu co-doping. The optimized LMNCO-0.050 electrode exhibits a higher initial discharge capacity of 128.1 mA h g−1 than the un-doped LMO electrode of 120.6 mA h g−1 at 1 C and room temperature. In particular, the LMNCO-0.050 electrode achieves high initial discharge specific capacities of 111.3 and 106.8 mA h g−1 at high rates of 5 C and 10 C, corresponding to excellent retention rates of 70.89% and 77.43% after 1000 cycles. Moreover, the excellent retention of 41.89% of the LMNCO-0.050 electrode after 1000 ultra-long cycles at 55 °C and 1 C can be attributed to the improved structural stability of the LiMn2O4 by Ni–Cu co-doping.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2021
·Vol. 11
·期 25
·14891-14898
·
IF 3.361
Junyu Xiang,Pengxue Zhang,Shixian Lv,Yongjun Ma,Qi Zhao,Yan Sui,Yuncheng Ye,Chuanli Qin
Spinel LiMn2O4 (LMO) with a three-dimensional structure has become one of the cathode materials that has gained the most interest due to its safety, low price and abundant resources. However, the lithium ion transmission is limited by large particle size and particle agglomeration of LMO. Thus, reducing the particle size and agglomeration of LMO can effectively improve its lithium ion transmission. Here, we synthesized a LMO cathode material with a nanoscale crystal size using the flexible expanded graphite (EG) soft template and Pichini method. EG-controlled particle size and particle agglomeration of LMO is conducive to charge transfer and diffusion of lithium ions between LMO and the electrolyte, meanwhile, there are more redox sites on the nanosized LMO particles, which makes the redox reaction of LMO more thorough during the charge and discharge process, resulting in high capacitance performance. In order to obtain the considerably required lithium-ion capacitors (LICs) with high energy density and power density, we assembled aqueous LMO//activated carbon (AC) LICs with 5 M LiNO3 as the aqueous electrolytes, which are environmentally friendly, safe, low cost and have higher electrical conductivity than organic electrolytes. The optimal LIC has an energy density of 32.63 W h kg−1 at a power density of 500 W kg−1 and an energy density of 8.06 W h kg−1 at a power density of 10 000 W kg−1, which is higher than most of the LMO-based LICs in previous reports. After 2000 cycles, the specific capacitance retention rate was 75.9% at a current density of 3 A g−1. Therefore, our aqueous LMO//AC LICs synthesized by the soft template/Pichini method have wide prospects and are suitable for low-cost, high-safety and high-power applications.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ELECTROCHEMISTRY COMMUNICATIONS
·
2022
·
IF 5.443
Hao Li,Liang Xue,Mingzhu Ni,Serguei V. Savilov,Sergey M. Aldoshin,Hui Xia
Spinel LiMn 2 O 4 (LMO) is a promising cathode material for lithium-ion batteries (LIBs) due to its low cost, high safety, and high energy density. However, surface dissolution of manganese and irreversible phase transitions reduce its long-term cycling performance. Although surface coating is a promising strategy for improving the structural stability of LMO, the commonly used coating process is tedious and complicated. In this work, a one-step sintering process is developed to prepare LMO materials coated in situ with MnBO 3 . It is found that the MnBO 3 layer formed in this way is uniformly coated on the surface of LMO, and effectively suppresses Mn dissolution and undesirable phase transition during repeated charge/discharge cycles. Furthermore, the MnBO 3 -coated LMO has improved electrode kinetics, demonstrating significantly improved rate performance compared to the pristine LMO. As a result, the optimized LMO sample exhibits 85.2% capacity retention after 1000 cycles at 1 C and still can deliver 96 mAh g −1 , even at 5 C. This work proposes a facile and efficient coating strategy for improving the electrochemical performance of LMO as a cathode material for LIBs.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2023
·
IF 6.6
Guiying Tian,Jian Gao,Minrui Wang,Xintao Wen,Yutong Liu,Jun Xiang,Lei Zhang,Penggao Cheng,Jianping Zhang,Na Tang
Current explosive demand in raw lithium greatly boosts lithium mining, and electrochemical Li-extraction using spinel LiMn 2 O 4 (LMO) from original brine has gained much attentions. In this study, Cr-doped LMO is prepared via a facile precipitation-calcination to elucidate the structural alterations and suppress Jahn-Teller distortion, and a novel hybrid capacitive deionization (HCDI) system of “Li-poor LiMn 1.8 Cr 0.2 O 4 ||brine (recovery liquid)||activated carbon” is constructed for electrochemical Li-extraction. The results prove that Cr-doping effectively suppresses Mn 3+ disproportionation induced by Jahn–Teller distortion, leading to a stabilized spinel framework for long lifespan. Importantly, the Cr-doping LMO realizes a stable (de)lithiation over 500 cycles with low manganese dissolution rate of 0.027% per cycle. Meanwhile, the Li-extraction capacity can reach 22 mg g −1 in 1.0 M LiCl electrolyte with retention rate of 86.05% after 500 cycles. In the assembled HCDI system, average Li-extraction capacity in brine reaches ∼15 mg g −1 after 15 cycles. Therefore, the HCDI system using Cr-doping LMO could introduce a new perspective for the industrial Li-extraction facing original brine.
研究领域:
材料科学
·
电化学
·
能源存储
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）