ELECTROCHIMICA ACTA
·
2019
·
IF 5.383
Aijia Wei,Wen Li,Qian Chang,Xue Bai,Rui He,Lihui Zhang,Zhenfa Liu,Yanji Wang
Mg 2+ /F − co-doped LiNi 0.5 Mn 1.5 O 4 cathode material was synthesized by a facile one-step solid-state process. The effect of Mg 2+ /F − co-doping on grain morphology, phase structure, and electrochemical properties was studied by a series of characterizations. Scanning-electron-microscopy images show that Mg 2+ /F − co-doped LiNi 0.5 Mn 1.5 O 4 (denoted LNMO-MF) particles grow larger than pure LiNi 0.5 Mn 1.5 O 4 particles. X-ray diffraction, Raman spectra , Fourier transformation infrared spectroscopy , X-ray photoelectron spectroscopy, and cyclic-voltammetry tests indicate that all samples mainly display a Fd -3m space group and more Mn 3+ ions in the LNMO-MF sample after Mg 2+ /F − co-doping, which is conducive to increasing the cationic disorder degree and enhancing the electronic conductivity of electrode material. Results show that the LNMO-MF cathode material delivers an excellent rate performance with discharge capacities of 142, 144, 140 136, 132, 124, 115, and 100 mAh g −1 at 0.2, 0.5, 1, 2, 3, 5, 7, and 10C (1C = 140 mAh g −1 ), respectively. Remarkably, LNMO-MF also shows cycling stability with a capacity retention of 86.2% at 5C after 400 cycles, which is much higher than that of pure LiNi 0.5 Mn 1.5 O 4 (67.7%). The improvement of LNMO-MF's electrochemical properties could be ascribed to the Mg 2+ /F − co-doping, delivering a more stable structure, better crystallinity , the highest Li + diffusion coefficient , and the lowest charge-transfer resistance.
研究领域:
材料科学
·
电化学
·
无机非金属材料
·
能源存储
·
锂离子电池
·
固态化学
·
功能材料
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DOI
高影响因子
Small
·
2024
·Vol. 20
·期 36
·2401497
·
IF 13
Shiqi Liu,Jie Wan,Boya Wang,Chenghan Li,Yulong Wang,Lin Wang,Haipeng Wu,Nian Zhang,Xu Zhang,Haijun Yu
Manganese-based lithium-rich layered oxides (Mn-LLOs) are promising candidate cathode materials for lithium-ion batteries, however, the severe voltage decay during cycling is the most concern for their practical applications. Herein, an Mn-based composite nanostructure constructed Li 2 MnO 3 (LMO@Li 2 MnO 3 ) is developed via an ultrathin amorphous functional oxide Li x MnO y coating at the grain surface. Due to the thin and universal LMO amorphous surface layer etched from the lithiation process by the high-concentration alkaline solution, the structural and interfacial stability of Li 2 MnO 3 are enhanced apparently, showing the significantly improved voltage maintenance, cycle stability, and energy density. In particular, the LMO@Li 2 MnO 3 cathode exhibits zero voltage decay over 200 cycles. Combining with ex situ spectroscopic and microscopic techniques, the Mn 2+/4+ coexisted behavior of the amorphous LMO is revealed, which enables the stable electrochemistry of Li 2 MnO 3 . This work provides new possible routes for suppressing the voltage decay of Mn-LLOs by modifying with the composite functional unit construction.
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DOI
高影响因子
Results in Physics
·
2019
·
IF 3.042
Yang Zhou,Xiaoyuan Liu,Ke Wang,Jing Li,Xinglai Zhang,Xin Jin,Xinyue Tang,Xiuhui Zhu,Ruishi Zhang,Xin Jiang,Baodan Liu
Series of “Hopcalite” catalysts for low-temperature CO oxidation are prepared through a facile ultra-sonic spray pyrolysis approach. It has been found that the spray pyrolysis temperature and Cu/Mn atomic ratio in initial precursors show significant impacts on the catalytic activity of Cu-Mn-O catalysts. The catalyst synthesized at 550 °C with Cu/Mn = 1/2 in precursor (Cu1Mn2-550) shows the highest catalytic activity towards CO oxidation (T 100 = 63 °C; E a = 17.04 KJ mol −1 ), owing to the formation of CuMn 2 O 4 phase with poor crystallinity. The synergistic effect of Cu and Mn species in spinel Cu-Mn-O phases attributes to the evaluated catalytic activity compared with those of pure oxides of copper or manganese towards CO oxidation. The results reveal that Cu1Mn2-550 not only provides more defects and vacancies to create more active sites, but also generates more highly active Cu (II) to promote CO oxidation. On the contrary, the decreasing amount of Cu (II) and the higher degree of crystallinity resulting from higher synthesis temperature lead to the deterioration of catalytic activity. Moreover, the phase transformation among the Cu x Mn 3-x O 4 spinels also shows significant effect on CO conversion rate. Finally, the formation mechanism of Cu-Mn-O catalysts and related CO oxidation process are discussed based on series of characterizations.
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DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2023
·
IF 5.5
Jiacheng Xu,Tiantian Zhang,Yan Sun,Shiyu Fang,Zuliang Wu,Jiali Zhu,Lianxin Dai,Weihua Liu,Buhe Zhang,Junwei Zhang,Shuiliang Yao,Erhao Gao,Jing Li
MnO 2 is a promising catalyst due to its abundant metal valence and good redox ability. Different crystal phases of MnO 2 have different oxygen species, but the relationship between their catalytic activity and crystal structures is unclear. In this study, four MnO 2 catalysts with crystal structures ( α -, β -, γ -, and δ -MnO 2 ) were selected to unveil the roles of terminal-type (Mn O), superoxide-type Mn(-O-) 2 Mn, and bridge-type (Mn-O-Mn) oxygen species in CO oxidation . γ -MnO 2 has the best CO oxidation performance. Density functional theory calculation results show that Mn O on γ- MnO 2 can adsorb CO easier than other two types of oxygen species. Operando TPR-DRIFTS-MS results show that Mn O on the surface of γ- MnO 2 can react with CO to form terminal-type oxygen vacancies (M 2+ =□ 2– ) at low temperatures. Meanwhiles, Mn(-□-)(-O-)Mn and Mn-□-Mn can dissociate O 2 to form Mn O under certain conditions to promote CO oxidation. MnO 2 catalysts with more Mn O oxygen species are of great significance for CO oxidation at a low temperature.
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DOI
高影响因子
Advanced Energy Materials
·
2023
·Vol. 13
·期 27
·2300746
·
IF 27.8
Yaoshen Niu,Zilin Hu,Bo Zhang,Dongdong Xiao,Huican Mao,Lin Zhou,Feixiang Ding,Yuan Liu,Yang Yang,Juping Xu,Wen Yin,Nian Zhang,Zhiwei Li,Xiqian Yu,Hao Hu,Yaxiang Lu,Xiaohui Rong,Ju Li,Yong-Sheng Hu
Na-ion batteries (NIBs) are promising for grid-scale energy storage applications. However, the lack of Co, Ni-free cathode materials has made them less cost-effective. In this work, Mg 2+ is successfully utilized to activate the oxygen redox reaction in earth-abundant Fe/Mn-based layered cathodes to achieve reversible hybrid anionic and cationic redox capacities. A high first charge capacity of ≈210 mAh g −1 with balanced charge–discharge efficiency is achieved without O-loss, showing a promising energy cost of $2.02 kWh −1 . Full cell against hard carbon anode without pre-sodiation shows energy density exceeding ≈280 Wh kg −1 with a decent capacity retention of 85.6% after 100 cycles. A comprehensive analysis of the charge compensation mechanisms and structural evolution is conducted. Voltage and capacity loss resulting from partially reversible Fe 3+ migration to the Na layer is confirmed, shedding light on further improvements for low-cost NIB cathodes in application scenarios.
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DOI
高影响因子
Journal of Water Process Engineering
·
2025
·
IF 6.7
Yaoyu Yan,Shuchen Sun,Jing Wei,A. Shubo,Faxin Xiao,Ganfeng Tu
Electrolytic manganese residue (EMR), a hazardous solid waste from electrolytic manganese metal (EMM) production, poses serious environmental risks due to its complex mineralogy and heavy metal mobility. However, it also holds potential as a secondary resource. We establish an end-to-end waste-to-materials flowsheet—sulfuric-acid curing → water leaching → impurity removal → one-step conversion—that selectively recovers Mn from EMR and upgrades it to phase-pure, high-value Mn₃O₄ nanomaterials. The effects of curing temperature and acid dosage on the leaching behaviors of Mn, Fe, Al, and Si were systematically investigated. At 240 °C and an acid dosage of 2.5 times the stoichiometric requirement, Mn leaching efficiency reached 95.35 %, while Si leaching remained below 50 % due to silicate encapsulation and gelation. Kinetic modeling using the shrinking core model revealed that Mn dissolution was primarily controlled by product-layer diffusion, with an apparent activation energy of 14–18 kJ·mol −1 . FTIR, XRD, SEM–EDS, and BET analyses showed that acid curing disrupted the dense silicate matrix and increased surface area from 9.4 to 55.6 m 2 ·g −1 . Mn 2+ in the purified leachate was directly precipitated and oxidized using an NH₃·H₂O–H₂O₂–EDTA system, producing uniformly sized Mn₃O₄ nanoparticles. Rather than a stand-alone synthesis, the impurity-tolerant process with defined operating windows is the core contribution, with the Mn₃O₄ product validating this waste-to-value pathway. This integrated route offers a scalable framework for hazardous-waste valorization while clarifying sulfuric-acid-curing transformation and leaching kinetics, advancing sustainable metal recovery.
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DOI
高影响因子
GREEN CHEMISTRY
·
2026
·
IF 10.6
Lei Yang,Jiacheng Gao,Min Su,Li Yua,Yuan Wang,Dajun Wang,Heng Zheng,Shaojun Yuan,Like Ouyang
The depolymerization of waste polyethylene terephthalate (PET) has predominantly focused on zinc-based catalysts, benefiting from their stable Lewis acidity derived from unique 3d orbital electronic configurations. In contrast, manganese-based catalytic materials, which share similar electronic structural features, have rarely been explored. This study developed a synergistic catalytic system using commercially available, low-cost homogeneous MnCl₂·4H₂O and heterogeneous Mn₂O₃ for the methanolysis of PET which achieved complete PET conversion within 1 hour at 180°C with a dimethyl terephthalate (DMT) yield of 95.35%. Compared with other catalytic systems for PET depolymerization, the present system uniquely integrates the capability of homogeneous Mn²⁺ ions to rapidly activate methanol and swell PET with the structural stability and ease of recovery inherent to the heterogeneous Mn₂O₃ oxide. Through systematic in-situ and ex-situ characterizations (XRD, XPS, in-situ DRIFTS, etc.), it was revealed that the essence of the synergistic effect originates from a dynamic composite active center formed at the interface between Mn²⁺ and Mn₂O₃, which efficiently stabilizes key reaction intermediates and promotes product desorption. Aspen Plus process simulation and economic analysis further validate its industrial potential: although the synergistic system introduces an additional step for homogeneous catalyst recovery, its superior product yield and lower activation energy grant it significant economic advantages and industrial potential. In summary, this work establishes a novel homo-heterogeneous catalytic system, offering a strategic approach to develop efficient and scalable solutions for polyester degradation.
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DOI
高影响因子
ACS Applied Materials & Interfaces
·
2019
·
IF 8.456
Yin Xie,Yongcheng Jin,Lan Xiang
The nontoxicity and low cost make LiMn2O4 a competitive cathode material for lithium-ion batteries. LiMn2O4 has a high theoretical capacity (296 mAh g–1) when cycled in the 3 and 4 V regions. However, it displays a low practical capacity (∼120 mAh g–1) because of the unavailability of the 3 V region caused by severe Jahn–Teller distortion. The present work investigated the full utilization of LiMn2O4 in both 3 and 4 V by tuning the nanoscale interfacial properties. Li-rich structures at the surface and interface of the spinel material and nanograin strain were introduced to improve the performances and were achieved by grinding LiMn2O4 and Li2O at 700 rpm for 10 h under an argon atmosphere. The product shows a high initial discharge capacity of 287.9 mAh g–1 at 0.05 C between 1.2 and 4.6 V and retains 83.2% of the capacity after 50 cycles. The nanoscale interfacial structure was clarified by spherical aberration-corrected microscopy and XRD refinement, and complex occupancies of Li and Mn were found at the interface. A correlation between the interfacial properties and electrochemical performance was established, and the improved performance could be attributed to the polycrystalline nature of the material, the unique Li-rich interfacial structure, and the slightly elevated valence state of Mn. The present results may provide insight for further evaluating the complex mechanism of controlling the electrochemical performance of LiMn2O4.
研究领域:
材料科学
·
电化学
·
储能
·
锂离子电池
·
纳米材料
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DOI
高影响因子
Inorganic Chemistry Frontiers
·
2017
·Vol. 5
·期 3
·635-642
·
IF 4.036
Di Tian,Xiaofeng Lu,Guangdi Nie,Mu Gao,Ce Wang
Currently, the search for the fabrication of inexpensive and efficient binder-free electrodes for high performance supercapacitor applications is still a great challenge. In this work, different nanostructures of Ni–Mn oxide (Ni–Mn–O) are directly grown on the surface of flexible electrospun carbon nanofibers (ECNFs) and further used as binder-free electrodes for supercapacitors. Among three typical nanostructures, Ni–Mn–O nanosheets on ECNFs show superior electrochemical properties with a good specific capacitance (368.6 F g−1) and excellent rate properties (88.6% retention at 20 times initial current density) in a three-electrode system. Furthermore, an aqueous symmetry cell and a solid-state symmetry supercapacitor are assembled using two pieces of flexible ECNFs@Ni–Mn–O nanosheets. The maximum energy density and power density based on the solid-state supercapacitor are up to 20.4 W h kg−1 and 5.2 kW kg−1, respectively, indicating that the flexible ECNFs@Ni–Mn–O nanosheets present a fairly promising future for practical applications in the field of energy storage.
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DOI
高影响因子
Reaction Kinetics Mechanisms and Catalysis
·
2025
·
IF 1.7
Cheng Lijun,Lei Juan,Ren Xiaoli,Chang Hong,Ju Baihe
In this study, a series of La-α-MnO 2 catalysts with different La doping amounts were prepared by hydrothermal method. It was found that the introduction of La could reduce the crystallinity of α-MnO 2 and increase the specific surface area of the catalyst. Furthermore, La doping can significantly weaken the Mn–O bond, increase the surface Mn 3+ and O ads content, and enhance the oxygen mobility and low-temperature reducibility. The catalytic results indicated that La doping could significantly improve the catalytic oxidation performance of toluene, and 1%La-α-MnO 2 catalyst exhibited the best catalytic activity for toluene oxidation. The toluene conversion rate reaches 90% when the reaction temperature is only 215 °C. In addition, 1%La-α-MnO 2 catalyst presented good stability and repeatability during 50 h durability test under water vapor.
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DOI
高影响因子
JOURNAL OF NANOBIOTECHNOLOGY
·
2026
·
IF 15
Deng Xu,Xie Xixiang,Zhou Xing,Jiang Lanfang,Zhu Tao,Su Rixiang,Chen Chunmei,Chen Wan,Chen Chunxia
The therapeutic efficacy of ischemic stroke (IS) treatment is severely limited by insufficient accumulation of therapeutic agents within ischemic lesions and persistent secondary injury after ischemia–reperfusion. Herein, we report a cRGD-functionalized exosome-based nanoplatform that enhances ischemic lesion-associated accumulation and antioxidative neuroprotection for the treatment of IS. Neural stem cell-derived exosomes were functionalized with cyclic RGD peptides (cRGD) and subsequently loaded with Mn₃O₄ nanoparticles to construct a hybrid nanosystem (cRGD-Exo@Mn₃O₄). The engineered exosomes preserve intrinsic brain tropism, while cRGD modification promotes preferential accumulation in ischemic regions, potentially through interaction with α v β 3 integrin that is upregulated in ischemic lesions. The incorporated Mn₃O₄ nanoparticles confer robust reactive oxygen species (ROS) scavenging capability, thereby mitigating oxidative stress in ischemic microenvironments. In vitro and in vivo studies demonstrate that cRGD-Exo@Mn₃O₄ exhibits enhanced accumulation in ischemic regions compared with non-modified counterparts. The nanosystem effectively attenuates oxidative stress and neuroinflammation, leading to reduced infarct volume, alleviation of cerebral edema, and improved neurological function in MCAO/R mice. Mechanistically, transcriptomic analysis suggests that the therapeutic effects are associated with modulation of inflammation-and cell death-related pathways, including suppression of the RIPK1/RIPK3/MLKL signaling cascade. Collectively, this study presents a rationally designed exosome-based nanoplatform integrating ischemic lesion-associated accumulation with ROS-scavenging capability. Graphical abstract
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高影响因子
Advanced Healthcare Materials
·
2026
·
IF 11
Xiaoling Liu,Run Huang,Ling Zou,Lu Yang,Yonghui Wu,Dandan Li,Jinbao Li,Jian He,Xiaochao Yang
Oxidative stress caused by the excessive accumulation of reactive oxygen species (ROS) plays a critical role in the development of acute respiratory distress syndrome (ARDS). Current antioxidant therapies using organic ROS scavengers fail in decreasing mortality due to the low ROS scavenging activity and fast metabolic rate. Inorganic ROS scavenging nanoparticles provide potential options for investigating ARDS antioxidant therapy. However, previous studies mainly focus on the ROS scavenging activity of these nanoparticles, while their capability to modulate the endogenous antioxidant system remains largely unexplored. Herein, mesoporous Ce–Mn–O bimetallic oxide nanoparticles (NP CeMn ) are designed and synthesized to activate the endogenous antioxidant system for ARDS therapy. Morphologically similar ceria nanoparticles (NP Ce ) and manganese oxide nanoparticles (NP Mn ) are used for comparison. In vivo and in vitro results demonstrate that NP Ce and NP Mn can promote the expression of SOD1 and SOD2, respectively, while NP CeMn can promote the expression of both SOD1 and SOD2. Mechanism studies establish a Keap1/Nrf2/SOD axis through which NP CeMn acts to activate the endogenous antioxidant system. Based on this property, NP CeMn can effectively alleviate oxidative stress and inflammation in the lung of the murine ARDS model. These findings suggest that activating the endogenous antioxidant system via inorganic nanoparticles is a promising ARDS therapeutic strategy.
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DOI
PubMed
高影响因子
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