CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Tianqi Jia,Geng Zhong,Sirong Lu,Xiaolong Ren,Yao Lv,Nanrui Li,Rui Yin,Guohuang Kang,Kangning Cai,Feiyu Kang,Yidan Cao
Active lithium loss, which is caused by parasitic reactions due to the instability of solid electrolyte interphase (SEI) on the anodes, results in fast capacity fade of batteries. Constructing robust SEI layer is an effective way to reduce active lithium loss. Herein, we propose a AgF-coated separator (AgF-CS) to facilitate robust LiF-rich SEI on the anode during initial cycle. Electrochemical analysis and microstructure investigations confirm the formation of the LiF-rich SEI on the anode induced by the fluoride-containing coating layer. The fluoride-containing interfacial layer not only effectively enhances the reversible capacity of the SiO anode even under lean electrolyte (14 μL mAh −1 ) condition, but also prolongs the cycling life of lithium metal batteries by reducing the consumption of electrolyte and active lithium. The initial Coulombic efficiency (ICE) of LiFePO 4 ||SiO full cell is increased from 43.68 % to 84.18 % with pretreatment by AgF-CS. As a result, the reversible capacity of LiFePO 4 ||SiO full cell is increased by ∼124 % in contrast with that of the unmodified one. The strategy proposed here, benefiting from the simple manufacture, provides a feasible way to alleviate active lithium loss and elevate energy density of rechargeable lithium batteries.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Pengfei Wei,Cen Qian,Luchao Ren
This study demonstrates the successful synthesis of (1- x )MgGa 2 O 4 - x LiF ( x = 0.1–0.4, mass fraction) ceramics via solid-state reaction, achieving a significant reduction in sintering temperature from 1410 to 850 °C. The XRD and Raman testing results showed the formation of a new phase of LiGaO 2 , which affected the dielectric properties. Variations in the sintering density and ionic polarizability cause changes in the permittivity. In addition, the packing fraction analysis of MgGa 2 O 4 , which influences the crystal structure stability, elucidates the intrinsic mechanisms affecting the dielectric loss. The composite effect makes the τ f value of the ceramic shift toward the negative value, owing to the large negative frequency temperature coefficient of LiF. Finally, (1- x )MgGa 2 O 4 - x LiF ( x = 0.3) sintered at 850 °C possesses the superior dielectric properties: ε r = 9.45, Q × f = 32,790 GHz, τ f = −28.5 ppm/°C (at 14 GHz). In addition, (1- x )MgGa 2 O 4 - x LiF ( x = 0.3) ceramics exhibit good cofiring compatibility with Ag electrodes promoting the ceramic to be a suitable candidate for LTCC applications.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
Materials
·
2024
·Vol. 17
·期 24
·6251
·
IF 3.1
Xing-Hua Ma,Qi Qu,Haitao Wu,Zhenlu Zhang,Xingyi Ma
M 2+ N 4+ Nb 2 O 8 -type ceramics (where M = Mg, Ca, Mn, Co, Ni, Zn and N = Ti, Zr) are essential for satellite communication and mobile base stations due to their medium relative permittivity ( ε r ) and high quality factor ( Q × f ). Although ZnTi 0.2 Zr 0.8 Nb 2 O 8 ceramic exhibits impressive microwave dielectric properties, including an ε r of 29.75, a Q × f of 107,303 GHz, and a τ f of −24.41 ppm/°C, its sintering temperature of 1150 °C remains a significant barrier for integration into low-temperature co-fired ceramic (LTCC) technologies. To overcome this limitation, a strategy involving the partial substitution of Zn 2+ with Cu 2+ and the addition of LiF as a sintering aid was devised for ZnTi 0.2 Zr 0.8 Nb 2 O 8 . The dual impact of Cu 2+ partial substitution and LiF as a sintering enhancer facilitated the successful sintering of Cu 0.3 Zn 0.7 Ti 0.2 Zr 0.8 Nb 2 O 8 ceramics at a reduced temperature of 950 °C using the conventional solid-state reaction method. These ceramics exhibited excellent microwave dielectric properties. Notably, Cu 0.3 Zn 0.7 Ti 0.2 Zr 0.8 Nb 2 O 8 ceramic with 40 mol% LiF addition demonstrated optimal microwave dielectric properties without any reaction with a silver electrode at a sintering temperature of 950 °C, yielding ε r = 32, Q × f = 45,543 GHz, and τ f = −43.5 ppm/°C.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2023
·
IF 9.5
Yue Lei,Xin Xu,Junying Yin,Sen Jiang,Kang Xi,Lai Wei,Yunfang Gao
Li-metal batteries (LMBs), especially in combination with high-energy-density Ni-rich materials, exhibit great potential for next-generation rechargeable Li batteries. Nevertheless, poor cathode–/anode–electrolyte interfaces (CEI/SEI) and hydrofluoric acid (HF) attack pose a threat to the electrochemical and safety performances of LMBs due to aggressive chemical and electrochemical reactivities of high-Ni materials, metallic Li, and carbonate-based electrolytes with the LiPF6 salt. Herein, the carbonate electrolyte based on LiPF6 is formulated by a multifunctional electrolyte additive pentafluorophenyl trifluoroacetate (PFTF) to adapt the Li/LiNi0.8Co0.1Mn0.1O2 (NCM811) battery. It is theoretically illustrated and experimentally revealed that HF elimination and the LiF-rich CEI/SEI films are successfully achieved via the chemical and electrochemical reactions of the PFTF additive. Significantly, the LiF-rich SEI film with high electrochemical kinetics facilitates Li homogeneous deposition and prevents dendritic Li from forming and growing. Benefiting from the collaborative protection of PFTF on the interfacial modification and HF capture, the capacity ratio of the Li/NCM811 battery is boosted by 22.4%, and the cycling stability of the symmetrical Li cell is expanded over 500 h. This provided strategy is conducive to the achievement of high-performance LMBs with Ni-rich materials by optimizing the electrolyte formula.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
LANGMUIR
·
2017
·
IF 3.833
Lan Zhang,Kaihang Zhang,Zhaohui Shi,Suojiang Zhang
Li4Ti5O12 (LTO) is a promising anode material for electric vehicles (EVs) and electrochemical energy storage applications because of its safety, good rate capability, and long cycle life. At elevated temperature, such as 60 °C, it always shows poor cycle performance because of the instability between the electrode material and electrolyte, which may also lead to a serious gassing issue. In this article, a facile hydrothermal method is adopted to coat the LTO powder with a thin LiF layer, in which the LiF acts as an artificial solid electrolyte interface (SEI) layer to prevent the direct contact of LTO and electrolyte, thus improving the high-temperature cycle performance. Electrochemical tests prove that the LiF coating layer has no influence on the kinetics at ambient temperature and greatly enhances the high-temperature cycle stability, and the LTO@LiF composite material keeps 87% of its initial discharge capacity in 300 1C cycles at 60 °C. Moreover, the LiF coating layer exhibits a special self-driven reforming process during the initial cycles, which makes it uniform and more effective at enhancing the stability between electrode/electrolyte interfaces.
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
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2022
·
IF 6.364
Xinglong Liu,Zexing Wang,Xinyao She,Quanliang Jia,Jiamao Li
In this study, LiF was utilized to decrease sintering temperature , improve microstructure, enhance Q × f , and regulate τ f of Li 2 Ti 0.9 (Zn 1/3 Ta 2/3 ) 0.1 O 3 (abbreviated as LTZT) ceramics. A complete solid solution together with a phase transition from monoclinic to cubic rock salt structure occurred. The cell volume of LTZT ceramics decreased as the LiF content increased. Relatively dense and uniform microstructures were observed for the ceramics as the LiF content was not less than 2 wt%. The dielectric constant of LTZT ceramics initially increased and then decreased with the increasing LiF content. The FWHM of the Raman band at about 808 cm −1 was closely related to the Q × f value. Notably, the samples with 3 wt% LiF exhibited the highest relative density of 97.4 % and satisfactory microwave dielectric properties of ε r = 23.14 ± 0.16, Q × f = 110,090 ± 1100 GHz, and τ f = +3.25 ± 1.45 ppm/°C when sintered at 950 °C. Good chemical compatibility with silver indicated the ceramic is a promising candidate in LTCC applications.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
Crystals
·
2022
·Vol. 12
·期 4
·512
·
IF 2.67
Zhijian Wang,Feng Pan,Lanlan Liu,Qifeng Du,Ruitao Tang,Jun Ai,Hong Zhang,Ying Chen
Mg2SiO4holds promise for its application in the microwave communication field due to its low dielectric constant and highQ×fvalue. However, its high negativeτfand high sintering temperature limit its application in low-temperature co-fired ceramic (LTCC) devices. In this work, Li2TiO3and CaTiO3were introduced to improve theτf, and LiF was chosen to decrease the sintering temperature. According to XRD patterns and SEM micrographs, the ceramic systems displayed a complex-phase structure, and the microstructure was densified when CaTiO3was added. All of the relative densities, dielectric constants, andQ×fvalues first increased and then decreased as the sintering temperature increased. The MLLC11.5 ceramics sintered at 800 °C could be obtained with the highestQ×fvalue of 54,581 GHz (at 8.06 GHz),εrof 14.13, andτfof + 5.81 ppm/°C. Furthermore, it was proven that the MLLC11.5 powders could be co-fired without any reaction with Ag powders at 800 °C, indicating its potential for LTCC application. The MLLC11.5 composition was used to prepare a GPS antenna and showed good prospects for its application in electronic communications.Keywords:Mg2SiO4-Li2TiO3-LiF-CaTiO3ceramics;structure;microwave dielectric property;LTCC;antenna
研究领域:
材料科学
·
电子工程
✓ 已验证
DOI
高影响因子
JOM
·
2019
·Vol. 72
·期 1
·239-246
·
IF 2.305
Peng Jianping,Wei Zheng,Di Yuezhong,Wang Yaowu,Sun Ting
NaF-KF-LiF-AlF 3 -based low-temperature electrolytes have attracted great interest because of their potential to optimize and improve current industrial aluminum production methods. In the present study, the saturated alumina solubility in quaternary NaF-KF-LiF-AlF 3 -based melts (total cryolite molar ratio \( {\text{CR}} = \left( {n_{\text{NaF}} + n_{\text{KF}} + n_{\text{LiF}} } \right)/n_{{{\text{AlF}}_{3} }} \) of 1.3) with both KF and LiF content of 0 mol.% to 20 mol.% were evaluated by measuring the weight loss of a rotating corundum disk over the temperature range of 800–920°C. The effects of the KF content, LiF content, and temperature on alumina solubility are discussed in detail. The results fit well with the following empirical equation within the temperature of 830–890°C: ω (Al 2 O 3 ) sat = A × ( t /1000) B , where A = 0.3101[KF] − 0.1254[LiF] − 0.0057[KF] 2 + 0.0028[LiF] 2 + 4.486, B = 0.3839[KF] + 0.0368[LiF] − 0.0140[KF] 2 + 0.0057[LiF] 2 + 4.913, and t is the temperature in Celsius. Alumina solubility diagrams at various temperatures are illustrated based on the empirical regression equation obtained. Finally, some problems and challenges preventing the application of these low-temperature melts in industry are discussed.
研究领域:
冶金学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Energy Technology
·
2024
·Vol. 12
·期 7
·2400188
·
IF 3.6
Chunfeng Meng,Zichuang Jiao,Mingjia Fang,Junfeng Chen,Heng Luo,Aihua Yuan
Metal-organic framework materials (MOFs) with hierarchical porosity, structural tunability, and rich redox-active centers have attracted intensive attention as potential substitutes for carbonaceous anode materials. However, the practical commercialization of MOFs still remains a challenge, due to uncontrollable performance degradation. Inspired by the prolonged lifespans of traditional anode materials with LiF-rich solid electrolyte interface (SEI), the roles of LiF are examined in enhancing the cycle stability of MOFs, with copper benzenedicarboxylate (Cu-BDC) as an example. By adjusting the electrolyte composition, the cycle performance of Cu-BDC material is optimized, due to the generation of LiF-rich SEI. In the optimal 3 M LiPF 6 electrolyte, the formed SEI membrane is the thinnest, and the LiF content is the highest, so the Cu-BDC shows a specific charge/discharge capacity of 378/387.2 mAh g −1 after 100 cycles at 100 mA g −1 , comparing to less than 200 mAh g −1 in the electrolyte with 1% vinyl carbonate.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Energy Chemistry
·
2022
·
IF 13.599
Junbo Zhang,Haikuo Zhang,Ruhong Li,Ling Lv,Di Lu,Shuoqing Zhang,Xuezhang Xiao,Shujiang Geng,Fuhui Wang,Tao Deng,Lixin Chen,Xiulin Fan
Passivation by the inorganic-rich solid electrolyte interphase (SEI), especially the LiF-rich SEI, is highly desirable to guarantee the durable lifespan of Li metal batteries (LMBs). Here, we report a diluent with the capability to facilitate the formation of LiF-rich SEI while avoiding the excess consumption of Li salts. Dissimilar to most of reported inert diluents, heptafluoro-1-methoxypropane (HM) is firstly demonstrated to cooperate with the decomposition of anions to generate LiF-rich SEI via releasing F-containing species near Li surface. The designed electrolyte consisting of 1.8 M LiFSI in the mixture of 1,2-dimethoxyethane (DME)/HM (2:1 by vol.) achieves excellent compatibility with both Li metal anodes (Coulombic efficiency ∼ 99.8%) and high-voltage cathodes (4.4 V LiNi 0.8 Mn 0.1 Co 0.1 O 2 (NMC811) and 4.5 V LiCoO 2 (LCO) vs Li + /Li). The 4.4 V Li (20 μm)||NMC811 (2.5 mA h cm −2 ) and 4.5 V Li (20 μm)||LCO (2.5 mA h cm −2 ) cells achieve capacity retentions of 80% over 560 cycles and 80% over 505 cycles, respectively. Meanwhile, the anode-free pouch cell delivers an energy density of ∼293 W h kg −1 initially and retains 70% of capacity after 100 deep cycles. This work highlights the critical impact of diluent on the SEI formation, and opens up a new direction for designing desirable interfacial chemistries to enable high-performance LMBs.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Small
·
2023
·Vol. 19
·期 49
·2303149
·
IF 13.3
Ping Li,Zhe Cheng,Jialu Liu,Lukang Che,Yingke Zhou,Enmin Xu,Xiaohui Tian,Zhongzhi Yuan
The electrode/electrolyte interfaces play an important role in the electrochemical reaction kinetics to alleviate the severe polarization and voltage hysteresis in lithium primary batteries. Herein, C 5 F 5 N is proposed as an electrolyte additive to tune the characteristics of the electrode/electrolyte interfaces. The Li/CF x primary battery with C 5 F 5 N additive exhibits an excellent discharge-specific capacity of 981.4 mAh g −1 (0.1 C), a remarkable high-rate capability of 598 mAh g −1 (15 C), and an outstanding energy/power density of 1068.7 Wh kg −1 /24362.5 W kg −1 . It also shows remarkable storage performance with 717.2 mAh g −1 at 0.1 C after storage at 55 °C for 2 months. The excellent performance of the Li/CF x batteries is closely related to the improved and stable Li 3 N/LiF-rich homogeneous interfaces induced by the C 5 F 5 N additive, which results in uniform distribution of Li + flux, facilitated electrochemical kinetics, and increased rate capability of Li/CF x battery. Therefore, C 5 F 5 N is expected to be a promising electrolyte additive, and the related electrode/electrolyte interface engineering provides an effective and facile strategy to increase the performance of the lithium primary battery.
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
Journal of Materials Chemistry A
·
2022
·Vol. 11
·期 3
·1351-1360
·
IF 14.511
Deqi Wang,Jie Liu,Tianyu Tan,Shishuo Liu,Guozhen Xu,Zhimiao Zhang,Yang Qin,Fengsheng Li
Boron (B) is the most suitable fuel for rocket ramjet. However, boron oxide (B2O3) on the surface of B causes many problems in its application. B2O3 cross-links with hydroxyl prepolymer, which reduces the processibility of the system. Moreover, B2O3 hinders contact between the oxidation component and internal active B. Consequently, B is difficult to ignite, and its reactivity and combustion efficiency are limited. To solve these problems, a dual-core–shell structure, B@LiF@AP, B embedded with LiF as core and AP as shell, has been designed and prepared. Its multi-effect synergies, improving processibility, protecting B from oxidation by AP before burning, decomposing B2O3, and improving reactivity and combustion efficiency, have been confirmed. Compared with the mixed sample of B and AP (B–AP), the heat release of B@LiF@AP increased by 211.10%. The combustion efficiency of B@LiF@AP increased by 42.60% more than that of B@AP. The ignition test showed that its ignition energy was reduced by 37.89% and the flame temperature increased by 26.27% than that of B–AP. The application and development of boron-based rocket ramjet will be accelerated because the application problems of B are solved by B@LiF@AP.
研究领域:
材料科学
·
航空航天工程
✓ 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）