JOURNAL OF POWER SOURCES
·
2014
·
IF 5.211
Yanhua Zhang,Fei Chen,Rong Tu,Qiang Shen,Lianmeng Zhang
High performance lithium ion conducting Li 7 La 3 Zr 2 O 12 solid electrolytes are prepared for the first time by field assisted sintering technology (FAST). The effect of sintering temperature on the phase compositions , microstructure and Li ionic conductivity is systematically investigated. The results show that pure cubic phase LLZO can be obtained at a range of temperatures from 1100 to 1180 °C for no more than 10 min. For the sample sintered at 1150 °C, a maximum relative density of 99.8% with a total ionic conductivity as high as 5.7 × 10 −4 S cm −1 are obtained at room temperature . This value is the highest among the present research. Compared with the traditional preparation methods, the current FAST is very promising to obtain high performance LLZO for its advantages of very short sintering time , a single preparation step of reaction-densification processing, and relatively lower sintering temperature.
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DOI
高影响因子
Journal of Energy Storage
·
2023
·
IF 9.4
Hongying Hou,Baoxiang Huang,Xiaohua Yu,Jian Lan,Sen Ming,Ju Rong,Xianxi Liu,Fangshu Chen
Organic/inorganic composite solid electrolyte has been a hot topic due to combining the merits of both components. Herein, a series of organic/inorganic composite solid electrolytes were prepared by casting method, in which polyvinylidene fluoride (PVDF) was modified with amphoteric sulfonate betaine (SB) and combined with the different contents (0 %, 10 %, 20 % and 30 %) of Li 7 La 3 Zr 2 O 12 (LLZO) and 20 % bis(trifluoromethane) sulphonyl (LiTFSI). The resultant samples were marked as 0%LLZO/SB-PVDF/LiTFSI, 10%LLZO/SB-PVDF/LiTFSI, 20%LLZO/SB-PVDF/LiTFSI and 30%LLZO/SB-PVDF/LiTFSI, respectively. As expected, composite solid electrolyte exhibited the desirable overall performances. Especially, 20%LLZO/SB-PVDF/LiTFSI membrane exhibited high ionic conductivity (1.73 × 10 −4 S/cm), wide electrochemical window (5.22 V), high Li + transference number (t Li + = 0.67) and high mechanical property, probably due to the synergistic effect of LLZO and amphoteric SB modification. Specifically, the amphoteric SB promoted the dissociation of LiTFSI and endowed PVDF matrix with the ionic conductivity, while LLZO facilitated high ionic conductivity, t Li + and mechanical property. Resultantly, Li//LiFePO 4 cell with 20%LLZO/SB-PVDF/LiTFSI membrane delivered 129.5 mAh/g at 1.0C for 200 cycles and 94.0 % capacity retention, demonstrating high application feasibility in the solid-state lithium ion battery . Furthermore, density functional theory (DFT) calculations showed that the binding energy of the amphoteric SB-Li + (C 11 H 21 NO 5 S-Li + ) system was 80.93 kcal/mol, higher than 75.55 kcal/mol of the LiTFSI system, indicating that the amphoteric SB could indeed promote the dissociation of LiTFSI.
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产品关联
DOI
高影响因子
Nanomaterials
·
2019
·Vol. 9
·期 5
·721
·
IF 4.034
Zhencai Dong,Chao Xu,Yongmin Wu,Weiping Tang,Shufeng Song,Jianyao Yao,Zhengyong Huang,Zhaoyin Wen,Li Lu,Ning Hu
Garnet Li7La3Zr2O12is one of the most promising solid electrolytes used for solid-state lithium batteries. However, low ionic conductivity impedes its application. Herein, we report Ta-doping garnets with compositions of Li7-xLa3Zr2-xTaxO12(0.1 ≤ x ≤ 0.75) obtained by solid-state reaction and free sintering, which was facilitated by graphene oxide (GO). Furthermore, to optimize Li6.6La3Zr1.6Ta0.4O12, Mg2+was select as a second dopant. The dual substitution of Ta5+for Zr4+and Mg2+for Li+with a composition of Li6.5Mg0.05La3Zr1.6Ta0.4O12showed an enhanced total ionic conductivity of 6.1 × 10−4S cm−1at room temperature. Additionally, spark plasma sintering (SPS) was applied to further densify the garnets and enhance their ionic conductivities. Both SPS specimens present higher conductivities than those produced by the conventional free sintering. At room temperature, the highest ionic conductivity of Li6.5Mg0.05La3Zr1.6Ta0.4O12sintered at 1000 °C is 8.8 × 10−4S cm−1, and that of Li6.6La3Zr1.6Ta0.4O12sintered at 1050 °C is 1.18 × 10−3S cm−1.Keywords:garnet;dual substitution;spark plasma sintering;conductivity
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产品关联
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2016
·
IF 2.758
Zhongli Hu,Hongdong Liu,Haibo Ruan,Rong Hu,Yongyao Su,Lei Zhang
Li 7 La 3 Zr 2 O 12 (LLZO) has cubic garnet type structure and is a promising solid electrolyte for next-generation Li-ion batteries. In this work, Al-doped LLZO was prepared via conventional solid-state reaction. The effects of sintering temperature and Al doping content on the structure and Li-ion conductivity of LLZO were investigated. The phase composition of the products was confirmed to be cubic LLZO via XRD . The morphology and chemical composition of calcined powders were investigated with SEM, EDS , and TEM . The Li-ion conductivity was measured by AC impedance. The results indicated the optimum sintering temperature range is 800–950 °C, the appropriate molar ratio of LiOH·H 2 O, La(OH) 3 , ZrO 2 and Al 2 O 3 is 7.7:3:2:(0.2–0.4), and the Li-ion conductivity of LLZO sintered at 900 °C with 0.3 mol of Al-doped was 2.11×10 −4 S cm −1 at 25 °C.
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产品关联
DOI
高影响因子
ACS Applied Energy Materials
·
2020
·
IF 4.473
Chao Chen,Yao Sun,Linchun He,Masashi Kotobuki,Emil Hanc,Yu Chen,Kaiyang Zeng,Li Lu
The Garnet-type solid electrolyte Li7La3Zr2O12 (LLZO) showing high ionic conductivity and a wide electrochemical potential window is considered as one of the most promising candidates for solid-state batteries. Among various doping derivatives, the Al- and Ga-doped LLZO electrolytes are intensively studied because of their ability to enhance the stability of the cubic structure and to promote good sinter ability as well. Despite showing great similarities in site preference and sintering behavior, the Al and Ga doping derivatives differ by 1 order of magnitude in total ionic conductivity. Therefore, a comparative study on the doping characteristics of Al and Ga with respect to ionic conductivity and sintering behavior is necessary. Herein, we simultaneously introduced Al and Ga into Li sites (AlxGa0.25–x-LLZO) to study their influences on the microstructure and electrochemical properties of LLZO. The results show that Ga doping enables a higher conductivity than Al doping and largely promotes sinter ability at the same time. Compared to Al single doping (Al0.25), Ga-contained compositions (x < 0.25) show significant grain growth. Moreover, a slight inclusion of Ga (Al0.20Ga0.05) not only modifies the sintering behavior that results in a microstructure transition from fine grains of Al0.25 (5–20 μm) to abnormally large grains (several hundred micrometers) but also greatly enhances the conductivity, yielding a value that is 3 times higher. However, further increases in Ga ratio in AlxGa0.25–x results in marginal increases in conductivity. The total conductivity reaches a maximum of 1.19 × 10–3 S cm–1 for Ga single doping (Ga0.25) at room temperature. In addition, Al0.25 also shows fast ion conducting behavior along the grain boundaries with a conductivity of 8.30 × 10–4 S cm–1. Consequently, this study sheds lights on the different doping characteristics between Al and Ga, providing guidance for fine composition engineering of these two promising dopants.
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DOI
高影响因子
ELECTROCHIMICA ACTA
·
2022
·
IF 7.336
Xiaoning Ma,Youlong Xu
ABSTRACT Cubic garnet Li 7 La 3 Zr 2 O 12 (LLZO) solid electrolytes have a strong potential to allow solid-state lithium-ion to become the next-generation energy storage systems and for addressing the safety issues. However, the applications of LLZO solid electrolytes are seriously limited by the relatively low critical current density of LLZO. In this study, we introduce lithium bromide (LiBr) with a low melting point as the sintering aid to prepare a high-performance garnet with high ionic conductivity , high relative density, and excellent critical current density. The prepared LLZO solid electrolyte with a LiBr concentration of 0.15 ( x LiBr–LLZO with x = 0.15 mol) exhibited a high ionic conductivity of 7.62 × 10 −4 S cm −1 at 25 ℃ with an excellent relative density of 96.27%. The critical current density (CCD) of the symmetric Li | 0.15LiBr–LLZO | Li cell was 1.0 mA cm −2 at 25 ℃. Furthermore, this cell can stably operate for 1000 h under a current density of 0.3 mA cm −2 . In addition, quasi-solid-state batteries of Li | LiFePO 4 with 0.15LiBr–LLZO electrolyte delivered excellent capacity retention (141.1 mAh g − 1 ; ∼89.7%) after 300 cycles, excellent rate performance, high coulombic efficiency and cycling stability. Furthermore, Li | LiNi 0.8 Co 0.1 Mn 0.1 O 2 with 0.15LiBr–LLZO electrolyte could run normally with high coulombic efficiency (>99%). These research results show that the solid-state batteries developed using 0.15LiBr–LLZO electrolyte are highly promising for the practical applications.
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DOI
高影响因子
ELECTROCHEMISTRY COMMUNICATIONS
·
2012
·
IF 4.859
Mian Huang,Alexandre Dumon,Ce-Wen Nan
The doping effect of Si, In and Ge in Li 7 La 3 Zr 2 O 12 (LLZ) as the solid electrolyte was studied via conventional solid-state reaction. The crystal structure, cross-sectional morphology, element distribution and conductivity were characterized for the undoped and doped LLZ ceramics. Our results showed that Si and In doping deteriorate electrical properties of LLZ as electrolyte, while Ge doping obviously improves properties. Ge might thus be a promising element for further increasing the ionic conductivity of LLZ ceramics.
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DOI
高影响因子
ELECTROCHIMICA ACTA
·
2017
·
IF 4.798
Fei Chen,Dunjie Yang,Wenping Zha,Bodi Zhu,Yanhua Zhang,Junyang Li,Yuping Gu,Qiang Shen,Lianmeng Zhang,Donald R. Sadoway
The advantages of all-solid-state batteries in terms of high energy density and improved safety have accelerated the research into durable and reliable solid electrolytes and into scale up of their processing technology. High lithium-ion-conducting Li 7 La 3 Zr 2 O 12 (LLZO) ceramic-based solid electrolytes have been intensively studied recently, but their widespread commercial deployment has been constrained due to their fragility and brittleness . In the present study, LLZO ceramic powders have been successfully incorporated into the polyethylene oxide (PEO) polymer by tape casting. The ionic conductivity of the PEO/LLZO composite electrolyte membranes is significantly enhanced at the optimal LLZO concentration of 7.5 wt.% at which the materials exhibits maximum ionic conductivity of 5.5 × 10 −4 S·cm −1 at 30 °C. The ionic conductivity enhancement mechanism of the composite electrolyte is revealed by differential scanning calorimetry (DSC), which shows that the LLZO filler represses crystallinity in PEO. Furthermore, as evidence of the advantageous electrochemical properties of the composite electrolyte an all-solid-state battery of LiFePO 4 /Li fabricated herein delivered a maximum discharge capacity of 150.1 mAh·g −1 at 0.1C, good cycling performance, and excellent rate capability under 60 °C.
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DOI
高影响因子
Journal of Energy Storage
·
2024
·
IF 8.9
Yanpeng Jia,Hongying Hou,Xianxi Liu,Xiaohua Yu,Ju Rong,An Lv,Yixuan Wang,Fangshu Chen
Garnet-type cubic Li 7 La 3 Zr 2 O 12 (LLZO) is widely considered as one of the most promising solid electrolyte candidates for the next-generation solid-state lithium batteries . However, high cost also limits the wide application of LLZO electrolyte. Allowing for the existence of trace hafnium (Hf) element in zirconium dioxide (ZrO 2 ) raw material and thus determining the threshold can significantly reduce the production cost of LLZO. Herein, the garnet-type xHf-LLZO solid electrolytes were synthesized at 1200 °C for 6 h using ZrO 2 raw material with different x mol% Hf (x = 0, 1.0, 1.8 and 2.7), in which 10 % sulfobetaine-modified polyvinylidene fluoride (SB-PVDF) was added for the composite electrolyte membranes in the solid state lithium cells. Furthermore, the effect of Hf element on the structure and electrochemical performances of LLZO solid electrolyte and the threshold of Hf in ZrO 2 were explored. The results showed that the tetragonal phase began to appear in LLZO when the molar ratio of Hf was 1.8 mol%, while the relative density and the room temperature ionic conductivity could remain 91.71 % and 1.08 × 10 −4 S/cm, respectively. The corresponding solid-state lithium cell delivered a specific discharge capacity of 130.2 mAh/g at 0.5C, and the capacity retention rate were as high as 90.7 % after 200 cycles at 1.0C. Seemingly, the threshold of Hf in ZrO 2 to prepare LLZO was about 1.8 mol%, thus reducing the cost for large-scale production of high-performance LLZO.
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DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2023
·Vol. 58
·期 48
·18003-18013
·
IF 4.5
Yang Yue,Ma Tianhui,Zhang Zheng
Cubic-phase Li 7 La 3 Zr 2 O 12 (LLZO) garnet is considered as a promising solid electrolyte due to high Li-ion conductivity and good chemical stability against electrode material. However, the desired cubic-phase formation of LLZO relies on the doping elements. To further improve the electrochemical performance and control the retention of lithium, a composite solid electrolyte based on Cu and Ta co-doped LLZO was fabricated by flash sintering (FS) in the present work due to the FS process characterized short sintering times and low furnace temperature, which could effectively restrain “Li-loss”. Based on the optimized Ta-LLZO conducted in our previous study, the effects of Cu 2+ content on the ionic conductivity and sintering behavior of the doped composites were discussed. The results show that Cu 2+ doping effectively stabilized the cubic structure of the co-doped composites and simultaneously promotes sinter-ability in FS process. Moreover, it is demonstrated that the room-temperature total conductivity of the Cu and Ta co-doped LLZO solid electrolyte is improved significantly by decreasing the grain boundary resistances and improving the densifications with the increasing of Cu 2+ content. In addition, the maximum ionic conductivity of 2.83 × 10 –3 S cm −1 and relative density 96.6% of the composite with Cu 2+ doping content 0.35 mol could be reached.
研究领域:
材料科学
·
固态离子学
·
陶瓷材料
·
能源材料
·
电化学
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DOI
高影响因子
International Journal of Electrochemical Science
·
2023
·Vol. 14
·期 10
·9695-9703
·
IF 1.5
Weijie Lan,Dongliang Lu,Ruirui Zhao,Hongyu Chen
Al2O3 crucible is commonly used during the sintering process of Li7La3Zr2O12 pellets, which always introduces unintentional Al-containing impurities to the final product. Rare investigations are focused on the mechanism of this crucible contamination up to now. Based on the study in this work, it is found that the extra Li2CO3 in the Li7La3Zr2O12 powder is a crucial factor in forming this kind of Al-containing impurities in the obtained pellets. The pyrolytic Li2O from Li2CO3 will react with Al2O3 at high temperature, forming liquid Li-Al-O eutectic and further promoting the dissolution of aluminum oxide crucible. Besides, the extra Li2CO3 can also affect the compactness and the distribution of Al element in the pellets, resulting in crystal structure transformation.
研究领域:
材料科学
·
固态化学
·
能源材料
·
陶瓷
·
电化学
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2022
·
IF 10.383
Xiaoning Ma,Youlong Xu
Garnet-type solid-state electrolyte Li7La3Zr2O12 (LLZO) is expected to realize the next generation of high-energy-density lithium-ion batteries. However, the severe dendrite penetration at the pores and grain boundaries inside the solid electrolyte hinders the practical application of LLZO. Here, it is reported that the desirable quality and dense garnet Li6.8Al0.2La3Zr2O11.80F0.20 can be obtained by fluoride anion doping, which can effectively facilitate grain nucleation and refine the grain; thereby, the ionic conductivity increased to 7.45 × 10–4 at 30 °C and the relative density reached to 95.4%. At the same time, we introduced a transition layer to build the Li6.8Al0.2La3Zr2O11.80F0.20-t electrolyte in order to supply a stable contact; as a result, the interface resistance of Li|Li6.8Al0.2La3Zr2O11.80F0.20-t decreases to 12.8 Ω cm2. The Li|Li6.8Al0.2La3Zr2O11.80F0.20-t|Li symmetric cell achieved a critical current density of 1.0 mA cm–2 at 25 °C, which could run stably for 1000 h without a short circuit at 0.3 mA cm–2 and 25 °C. Moreover, the Li|LiFePO4 battery exhibited a high Coulombic efficiency (>99.5%), an excellent rate capability, and a great capacity retention (123.7 mA h g–1, ≈80%) over 500 cycles at 0.3C and 25 °C. The Li|LiNi0.8Co0.1Mn0.1O2 cell operated well at 0.2C and 25 °C and delivered a high initial discharge capacity of 151.4 mA h g–1 with a good capacity retention (70%) after 195 cycles. This work demonstrates that the anion doping in LLZO is an effective method to prepare a dense garnet ceramic for the high-performance lithium batteries.
研究领域:
材料科学
·
电化学
·
储能技术
·
固态电池
·
陶瓷材料
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）