JOURNAL OF ALLOYS AND COMPOUNDS
·
2016
·
IF 3.014
Shengjie Liu,Hao Wu,Ling Huang,Mingwu Xiang,Heng Liu,Yun Zhang
Ni-rich ternary layered oxides , (LiNi x [M] 1−x O 2 , x ≥ 0.5, M = Co and Mn), have become one of the mainstream cathode materials for next-generation lithium-ion batteries due to their high capacity and cost efficiency compared with LiCoO 2 . However, the high-voltage operation of the Ni-rich oxides (>4.3 V) required for high capacity is inevitably accompanied with a rapid capacity decay over numerous cycles. In this work, we reported a surface coating of LiNi 0.6 Co 0.2 Mn 0.2 O 2 with Li 2 Si 2 O 5 via a facile and efficient synthetic approach, which involves the employment of silicic acid (H 2 SiO 3 ) as remover to react with the surface residual lithium compounds ( e.g. Li 2 CO 3 and LiOH) of LiNi 0.6 Co 0.2 Mn 0.2 O 2 and consequent formation of a robust and complete Li + -conductive Li 2 Si 2 O 5 protective coating layer . The structure and morphology of the coated cathode materials are fully characterized by using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Compared with the pristine LiNi 0.6 Co 0.2 Mn 0.2 O 2 , coating with the Li + -conductive Li 2 Si 2 O 5 is found to be very effective for improving the rate capability of the LiNi 0.6 Co 0.2 Mn 0.2 O 2 when evaluated at a high cut-off voltage up to 4.5 V. Specifically, 1 wt. % H 2 SiO 3 -treated LiNi 0.6 Co 0.2 Mn 0.2 O 2 electrode exhibits high discharge specific capacities of 213.9 and 121.6 mAh g −1 at 0.1 and 10 C, respectively, whereas the pristine electrode only shows 196.8 and 92.1 mAh g −1 . Besides, the surface-modified LiNi 0.6 Co 0.2 Mn 0.2 O 2 electrode also manifests an enhanced long-term cycling stability (67% capacity retention after 200 cycles at 5 C), much better than the pristine electrode (52% retention) due to the robust protective effect of the Li 2 Si 2 O 5 coating layer. All these results indicate that the Li 2 Si 2 O 5 -coated LiNi 0.6 Co 0.2 Mn 0.2 O 2 will be a promising cathode material for lithium-ion batteries with fascinating electrochemical energy storage capabilities.
研究领域:
电化学
·
材料科学
·
能源存储
·
锂离子电池技术
·
固态化学
·
表面改性
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2021
·Vol. 9
·期 32
·17261-17269
·
IF 12.732
Jinji Liang,Chenhan Lin,Xiangcong Meng,Min Liang,Jie Lai,Xuhong Zheng,Quanzhuang Huang,Liying Liu,Zhicong Shi
Mn-based layered oxides, as potential cathodes for potassium-ion batteries (PIBs), face major challenges such as consecutive phase transition, serious capacity loss, and sluggish K+ transport kinetics. Herein, Co–Mg co-substituted K0.45Co1/12Mg1/12Mn5/6O2 is designed as a promising cathode material for PIBs to conquer the above issues in this work. Co3+–Mg2+ ions occupying the Mn3+ sites are confirmed to effectively alleviate the Jahn–Teller distortion induced by Mn3+ ions. P3-K0.45Co1/12Mg1/12Mn5/6O2 exhibits highly reversible single-phase structural evolution during the K+ deintercalation/intercalation. In contrast, the pristine K0.45MnO2 electrode experiences incompletely reversible structural variation from a P′3 to P3 phase. The increase of structural stability in the Co–Mg co-substituted sample is the main reason leading to improved cycling stability. Moreover, K0.45Co1/12Mg1/12Mn5/6O2 delivers better rate capability resulting from faster K+ diffusion compared to K0.45MnO2. Therefore, Co–Mg co-substitution is an effective strategy to enhance the structural stability and electrochemical properties of Mn-based layered oxides in PIBs.
研究领域:
材料科学
·
电化学
·
能源存储
·
无机化学
·
固态化学
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电池技术
✓ 已验证
DOI
高影响因子
Small
·
2020
·Vol. 16
·期 43
·2004614
·
IF 11.459
Xian Wang,Anrui Dong,Ziyi Zhu,Lulu Chai,Junyang Ding,Li Zhong,Ting-Ting Li,Yue Hu,Jinjie Qian,Shaoming Huang
In the preparation of nanomaterials, the kinetics and thermodynamics in the reaction can significantly affect the structures and phases of nanocrystals. Therefore, people are keen to adopt various synthetic strategies to accurately assemble the target nanocrystals, and reveal the underlying mechanism of the formation of specific structures. In this work, the total reaction time is adjusted to let the prepared MnCo Prussian blue analogous (MnCoPBA) crystals show four evolving morphological changes at different stages with the assistance of sodium dodecyl sulfate. Furthermore, it is clearly observed that the epitaxial growth along the (100) plane on the shell of MnCoPBA nanocrystals is favored, and the thermodynamics and kinetics in the morphology change process are analyzed in detail. Through the simple pyrolysis, MnCoPBA crystals can be successfully converted into the corresponding carbon composites, of which Mn 2 Co 2 C nanoparticles are evenly distributed in highly graphitized carbon matrix. Among them, PBA-III-700 performs good oxygen reduction reaction performance in alkaline solution with the half-wave potential of 0.801 V and diffusion-limited current density of 5.36 mA cm −2 , and its zinc-air battery exhibits the peak power density of 103.4 mW cm −2 competitive with commercial Pt/C.
研究领域:
材料化学
·
纳米科学与技术
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电化学
·
能源材料
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无机功能材料
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
·
2021
·Vol. 45
·期 11
·16538-16550
·
IF 5.164
Sanchao Liu,Huihui He,Dongyun Zhang,Chengkang Chang
Summary To improve the electrochemical performances of high voltage LiCoMnO 4 spinel cathode material at 5.3 V, Cr doped LiCoMn 1-x Cr x O 4 ( x = 0, 0.025, 0.050, 0.075) materials were synthesized by a one-step solid-state at 750°C. Rietveld refinement results showed that the phase purity of spinel is promoted with the increase in Cr concentration, which can be explained by the strong Cr O bond that reduces oxygen deficiency and eliminates Li 2 MnO 3 impurity phase during the synthesis process. Such change in phase purity further causes the improvement in specific capacity, and the 5.0%Cr doped sample displays the best result with a value of 123.0 mAh/g at 0.1°C and 93.3 mAh/g at 10°C. For a comparison, the pristine sample only releases a capacity of 112.6 mAh/g at 0.1°C and 54.8 mAh/g at 10°C. Improved capacity retention, from 83.1% to 90.1% after 100 cycles at 1°C, is also observed due to the suppressed volume change during the redox process after the incorporation of Cr cations in the lattice. Promoted rate performance, attributed from the improved Li ion diffusion coefficient, is also confirmed in the experiment. The improvement of those electrochemical properties could be explained by high-phase purity and superior structural stability benefited from Cr-doping. Novelty statement LiCoMn 1-x Cr x O 4 ( x = 0, 0.025, 0.050, 0.075) materials were synthesized by a one-step solid-state at 750°C, Chromium had been confirmed to reduce oxygen loss during LiCoMnO 4 synthesis due to high oxygen affinity of Cr, which improves phase purity. As a result, the specific capacity was increased. Cr-doping enhances the structural stability so that capacity retention was promoted due to higher bond energy of Cr O than Mn O; rate performance was also enhanced due to the improved diffusion coefficient.
研究领域:
材料科学
·
电化学
·
储能
·
固态化学
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry C
·
2024
·
IF 5.7
Ruijing Fu,Junpeng Gao,Pinsen Zhang,Lingrui Wang,Bo Wang,Guangxia Wang,Xiaoshuang Li,Youchao Kong,Qingguang Zeng,Guanjun Xiao
Manganese (Mn)-based organic–inorganic metal halides (OIMHs) are extensively employed in various optical applications due to their non-toxicity, superior optical properties, and tunable emission advantages. Developing effective strategies to enhance the optical properties of these materials and clarifying their structure–optical property relationships continue to be of significant interest. Here, we report that the zero-dimensional (0D) (C24H20P)2MnBr4 exhibits remarkable pressure emission tuning that shifts from green to red, a phenomenon driven by the enhancement of the crystal field splitting energy and the reduced energy difference of the lowest d–d transition (4T1 → 6A1) motivated by the shortening of Mn–Br bonds. Additionally, the band gap value of (C24H20P)2MnBr4 becomes 3.13 eV, showing an unexpected decrease by 1.09 eV from an initial value of 4.22 eV, when the pressure is released from 31.0 GPa. The incomplete recovery of the distortion in [MnBr4]2− tetrahedra, impeded by the distortion of soft organic macromolecules, is believed to be responsible for band gap narrowing. Combined with computations and subsequent experiments, it is inferred that pressure induced reduction in the Mn–Br bond distance contributes to the distortion of tetrahedral [MnBr4]2− and larger-sized organic cations. Our work not only elucidates the structure–optical property relationships in Mn-based OIMHs, but also opens new avenues for modulating their optical properties and devising innovative strategies for designing novel Mn-based OIMHs.
研究领域:
材料科学
·
光学
·
化学
✓ 已验证
DOI
高影响因子
Journal of Environmental Sciences
·
2024
·
IF 5.9
Xixian Huang,Bing Yang,Ye Dou,Yang Ding
The abiotic oxidation of divalent manganese (Mn(II)) and the formation of Mn oxides are important geochemical processes, which control the mobility and availability of Mn as well as element cycling and pollutant behavior in soils. It was found that iron (oxyhydr)oxides can catalyze Mn(II) oxidation , but the effects of the coexisting dissolved organic matter (DOM) molecules on the catalysis of different iron (oxyhydr)oxides for Mn(II) oxidation are poorly understood. Herein, we investigated Mn(II) oxidation under the impacts of the interactions between iron (oxyhydr)oxides (i.e., ferrihydrite, goethite and hematite) and DOM molecules. Simultaneously, we elucidated the variations of DOM composition and properties. Our results indicated that the catalysis of iron (oxyhydr)oxides for Mn(II) oxidation was significantly inhibited by DOM. Moreover, DOM had less inhibiting effect on the catalysis of ferrihydrite for Mn(II) oxidation and the formation of Mn oxides (e.g., hausmannite and buserite) relative to goethite and hematite, which was partially because of the higher electron transfer capacities of ferrihydrite. Meanwhile, DOM molecules with high nominal oxidation state of carbon (NOSC), molecular weight, unsaturation and aromaticity were selectively adsorbed and oxidized by Mn oxides , including the oxygenated phenols and polyphenols. The newly formed molecules mainly belonged to phenols depleted of oxygen and aliphatics. Furthermore, NOSC was a key molecular characteristic for controlling DOM composition during DOM adsorption and oxidation by Mn oxides when iron minerals were present. Overall, our research contributes to understanding Mn(II) oxidation mechanisms under heterogeneous systems and behaviors of DOM molecules in the environment.
研究领域:
环境地球化学
·
土壤化学
·
水文地球化学
·
有机-矿物相互作用
·
元素生物地球化学循环
✓ 已验证
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2023
·Vol. 30
·期 46
·102880-102893
·
IF 5.8
Li Yunhe,Li Hao,Zhao Baogang,Ma Yanming,Liang Peiyuan,Sun Tianjun
The escalating levels of surface ozone concentration pose detrimental effects on public health and the environment. Catalytic decomposition presents an optimal solution for surface ozone removal. Nevertheless, catalyst still encounters challenges such as poisoning and deactivation in the high humidity environment. The influence of support on catalytic ozone decomposition was examined at a gas hourly space velocity of 300 L·g −1 ·h −1 and 85% relative humidity under ambient temperature using Cu-Mn–doped oxide catalysts synthesized via a straightforward coprecipitation method. Notably, the Cu-Mn/SiO 2 catalyst exhibited remarkable performance on ozone decomposition, achieving 98% ozone conversion and stability for 10 h. Further characterization analysis indicated that the catalyst’s enhanced water resistance and activity could be attributed to factors such as an increased number of active sites, a large surface area, abundant active oxygen species, and a lower Mn oxidation state. The catalytic environment created by mixed oxides can offer a clearer understanding of their synergistic effects on catalytic ozone decomposition, providing significant insights into the development of water-resistant catalysts with superior performance. Graphical
研究领域:
环境催化
·
大气污染控制
·
材料化学
·
表面科学
·
催化化学
·
环境工程
·
功能材料
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Zihao Su,Zhihao Guo,Haoyu Xie,Meizhen Qu,Gongchang Peng,Hao Wang
Li-rich Mn-based cathode materials (LLOs) are often faced with problems such as low initial Coulombic efficiency (ICE), limited rate performance, voltage decay, and structural instability. Addressing these problems with a single approach is challenging. To overcome these limitations, we developed an LLO with surface functionalization using a simple fabrication method. This two-step process involved a liquid-stage NaBF4 treatment followed by an in situ chemical reaction during sintering. This reaction led to the creation of oxygen vacancies (OV), spinel structures, and doping with Na at the Li site, B at the tetrahedral interstitial spaces of O in both the transition-metal (TM) layer and Li layers as well as the octahedral interstices in the TM layer, and F at the O site. We have carried out a thorough study and employed density functional theory calculations to reveal the hidden mechanisms. The treatment not only increases the electrical conductivity but also changes the oxygen charge environment and inhibits lattice oxygen activity. Surprisingly, the B–O bond is so strong that it prevents the migration of TM within the tetrahedral interstitial spaces of O in both the TM and Li layers, hence stabilizing its structure. This bonding interaction strengthens the transition of the TM 3d and O 2p states to lower energy levels, thus causing an increase in the redox potentials. Hence, a rise in the operating voltage occurs. Of special importance, this therapy dramatically increases the ICE to 90.29% and keeps a specified capacity of 203.3 mAh/g after 100 cycles at 1C, which is an excellent capacity retention of 89.94%. This study introduces ideas and methods to tackle the challenges associated with LLOs in batteries. It also provides compelling evidence for the development of high-energy-density Li-ion batteries.
研究领域:
材料科学
·
电化学
·
锂离子电池
·
固态化学
·
能源材料
·
表面工程
·
计算材料学
✓ 已验证
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2023
·
IF 9.2
Zhongshuai Zhang,Yuqing Liu,Zixi Liu,Hailin Li,Yaoliang Huang,Weijian Liu,Dingshan Ruan,Xin Cai,Xiaoyuan Yu
O3-type Fe/Mn-based layered oxides are considered as the competitive cathode materials for sodium-ion batteries because of environmental friendly metal elements and low cost. However, a lower capacity, poor cycling stability and irreversible phase transitions hinder their commercial application. Herein, the Cu-doped O3 biphasic Na[Mn 0.6 Fe 0.4 ] (1- x ) Cu x O 2 (NFMCu- x ) layered oxides are successfully synthesized by high temperature calcination using Fe/Mn-based Prussian blue analogues as precursor. The results indicate that the different stoichiometric of Cu 2+ substitution in P2 NaMn 0.6 Fe 0.4 O 2 can cause the transformation of P2 phase to O3 monophase or O3 biphase. The NFMCu- x samples exhibit O3 monophase at x = 0.1, 0.15, while O3 biphase coexists in the compound at x = 0.2, 0.25, and 0.3. Benefiting from the synergetic effect of Cu-doping and O3 biphasic structure, the optimized O3 biphasic NaMn 0.48 Fe 0.32 Cu 0.2 O 2 exhibits a high Na + diffusion coefficient and an excellent sodium storage performance with a high discharge specific capacity of 103.76 mAh g −1 at 24 mA g −1 and good capacity retention of 82.9% after 100 cycles. Moreover, Cu-doped O3 biphasic NaMn 0.48 Fe 0.32 Cu 0.2 O 2 features an excellent air stability. Thus, this work proposes a strategy in development of O3 Fe/Mn-based layered oxide as high-performance cathode materials for sodium-ion batteries.
研究领域:
材料科学
·
电化学
·
能源存储
·
无机化学
·
固态化学
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2024
·Vol. 59
·期 10
·4267-4280
·
IF 3.5
Chen Ling,Gan Qingbao,Xiao Xueqing,Cai Shuguang,Yan Xiaohui,Zheng Chan
Recent progress in the development of MnO 2 -based micromotors has shown the immense potential of these motile devices to remediate environmental contamination. However, the production of such micromotors on an industrial scale through a facile, efficient and reproducible process remains challenging. The present work aimed to address this issue using naturally occurring and abundant pine pollen (PP) grains. The immersion of PP in potassium permanganate (KMnO 4 ) solutions was found to generate MnO 2 nanoparticles (NPs) on the PP surfaces, the amount and distribution of which was readily adjusted by varying the coating time. Because of the asymmetrical shape of the PP grains, the MnO 2 /PP composites exhibited rapid self-propulsion at a maximum speed of 360.686 μm/s (approximately eight body lengths/s) in low-concentration hydrogen peroxide (H 2 O 2 ) solutions. The ability of these materials to remediate heavy metal pollutants was also examined and was evidently increased by a factor of 1.5 compared with static counterparts. These composites could also be recovered and reused over three consecutive cycles. The competitive cost, continuous motion and superior decontamination capacity of these materials suggests potential applications in the rapid removal or degradation of heavy metal ions, toxic organic dyes, pathogenic bacteria and other pollutants in wastewater. These micromotors represent a new approach to the utilization of natural materials in environmental remediation.
研究领域:
环境科学
·
纳米技术
·
材料科学
·
化学工程
·
污染控制
✓ 已验证
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2024
·
IF 8.2
Zhenzhen Jia,Qiuxin Liu,Jiatang Hu,Shiyu Li,Hujunjie Chen
Water hypoxia and metal pollution are commonly co-existed in urbanized estuaries. This study focuses on the effect of an extended dissolved oxygen (DO) full-life dynamics (86 days) on metal behavior across the sediment-water interface through laboratory microcosms from two typical zones in Pearl River Estuary. Combining our time-series results of concentrations and fluxes, it showed that Co, Ni, and Zn consistently presented a release-precipitation-release trajectory with an oxic-hypoxic-anoxic-reoxic transition, characterized with highly variable behavior in the hypoxic-anoxic hotmoments. In parallel, changing DO dynamics significantly activated a repartitioning process of Co, Ni, and Zn among several species and elevated their risk in sediments, promoting the formation of more labile species in the 0–10 mm hotspots, where metals sensitively responded. Over DO transition, metal cycling was tightly co-related with Fe, Mn, and S elements. It was found that Mn was dominated in low oxygen-hypoxic period, but switched to S and Fe in anoxic stage, limiting sustained metal liberation to overlying water. Enlarging this experiment to practice, released Zn fluxes from sediments in hypoxic summer could contribute about ∼2.0% to their stocks in water column, while increase to 20% (1 m bottom water) in highly-stratified zones. This study has certain significance in understanding the long-term metal behavior and fate in estuarine regions, even lakes and reservoirs.
研究领域:
环境科学
·
地球化学
·
水生生态学
·
污染生态学
·
生物地球化学
·
环境毒理学
·
河口学
✓ 已验证
DOI
高影响因子
Functional Materials Letters
·
2024
·
IF 1.2
Zhuqing Sun,Yongxia Li,Haowen Bai,Shenghang Jin,Haibo Zhang,Guanying Cao
All inorganic lead halide cesium perovskite quantum dots (QDs) have attracted much attention due to their excellent luminescence properties, but further development is restricted by their stability and the existence of toxic element lead. In this paper, F/Mn-doped CsPb ( Br / Cl ) 3 QDs glass was prepared by melt quenching and heat treatment, with reduced Pb content effectively. The result shows that the spectrum of the QD glass is adjustable between 450 nm and 515.4 nm by changing the feeding ratio of Mn-Pb ion and heat treatment temperature. Moreover, the indraught of Mn 2 + effectively improves the PLQY of CsPb ( Br / Cl ) 3 QDs glass and serves as a red-emitting. The prepared composites not only maintain good fluorescence characteristics, but also greatly improve the stability of QDs. And successfully coupled with blue LED chips to synthesize WLED, Under 20 mA current, the color coordinate is (0.3446, 0.3389).
研究领域:
材料科学
·
纳米技术
·
光电子学
·
固体物理
·
无机化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）