ELECTROCHIMICA ACTA
·
2013
·
IF 3.777
Mian Huang,Wei Xu,Yang Shen,Yuan-Hua Lin,Ce-Wen Nan
Ge-doped Li 7 La 3 Zr 2 O 12 (LLZ) is prepared via the conventional solid-state reaction. Our results showed that doping Ge of less than 1 wt% could stabilize the cubic phase of garnet-type LLZ and also increase its ionic conductivity up to 8.28 × 10 −4 S/cm at room temperature . When the content of Ge dopant is higher, GeO 2 impurity phase would appear and there coexists cubic and tetragonal mixed structures, lowering the conductivity. By combining X-ray absorption near-edge spectroscopy and full multiple-scattering theory, we find that Ge more likely enters into the Li and La crystallographic sites instead of the Zr site, which provides understanding of the micro-structural modulation by Ge dopants and the subsequent enhancement in the ionic conductivity.
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高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2025
·
IF 3.8
Run Yu,Yongjin Chen,Chengyu Li,Shaojun Wang,Pengcheng Li,Ruihan Tang,Cong Gao,Chuanlong Lin,Xiang Gao
The garnet-type oxide Li 7 La 3 Zr 2 O 12 solid-state electrolytes (SSEs) are considered as a reliable option in all-solid-state lithium batteries (ASSLBs) due to its excellent properties. However, it still faces challenges such as limited ionic conductivity and low air stability. In this work, Ga 3+ and Ta 5+ co-doped samples Li 7−3 x − y Ga x La 3 Zr 2− y Ta y O 12 (Ga x Ta y -LLZO) synthesized via the solid-state method are demonstrated to stabilize the cubic phase, regulate the concentration of Li vacancies in LLZO, and improving the Li + transport channels. As a result, the Ga0.1Ta0.3-LLZO sample achieves a high conductivity of ∼1 mS cm −1 . Furthermore, we discovered that in addition to the previously reported effects of decreasing grain boundary density and the inert LiGaO 2 secondary phase at grain boundaries, the synergistic effect of introducing multiple dopant ions, which enhances lattice stability, is also a key factor contributing to improved air stability. Our findings demonstrate that co-doping strategy with Ga 3+ /Ta 5+ is an effective method for simultaneously enhancing conductivity and air stability of LLZO, laying solid foundation for the application of SSEs in ASSLBs.
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高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2024
·Vol. 35
·期 9
·1-13
·
IF 2.8
Gong Zonggui,Wang Nanlan,Guo Haoxuan,Zhu Peishu,Wang Qijing,Yu Hang,Zhang Yu,Gao Min,Zheng Xinghua
Due to the increasingly urgent safety and energy density concerns of lithium-ion batteries, more and more attention has been attracted by the Li 7 La 3 Zr 2 O 12 (LLZO)-based solid electrolytes with high ion conductivity and chemical stability against Li-metal. However, to prepare the high-quality LLZO ceramic electrolyte with high-ion conductivity and density, there is still a big challenge of the serious “Li-loss” and the abnormal grain growth during the long-time high-temperature sintering process. A novel covered sintering method is put forward to prepare the high-quality Mo-doped LLZO (LLZMO) ceramic electrolyte. The sintering strategy effectively suppresses the Li-loss to obtain the LLZMO dense ceramics with cubic garnet phase and tight grain boundaries. The LLZMO ceramics sintered at lower temperature of 1050 °C for 2 h via the novel covered sintering exhibit high density ( ρ r = 92.3%) and high-ionic conductivity of 6.08 × 10 –4 S cm −1 at 25 °C, which are close to those of LLZO-based ceramics prepared by hot pressing sintering, ultrafast high-temperature sintering (UHS). The novel covered sintering provides an energy-saving, low-cost and high-efficient strategy to prepare the high-quality LLZO-based ceramics electrolyte.
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JOURNAL OF ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Yanhua Zhang,Xinglong Gao,Yuhang Mei,Zijun Tang,Dawei Luo,Jiadong Deng
The instability of Ta-doped Li 7 La 3 Zr 2 O 12 (LLZTO) solid electrolytes with Li anode has severely restricted the development of all-solid-state lithium batteries. Herein, a simple interlayer of graphite is constructed at the Li/LLZTO interface with pencil, and the electrochemical stability of the battery has been significantly improved. Results show that the internal resistance of battery modified by 2B type graphite interlayer is reduced more than 2 orders of magnitude than that of the unmodified battery. And the battery has good cycling stability at current density of 0.1 mA cm −2 with polarization voltage< 0.01 V after 200 cycles. Besides, it also has excellent high-current discharge performance in the range of 0.1 mA cm −2 ∼ 0.6 mA cm −2 with polarization voltage close to 0 V. SEM showed that before galvanostatic charge-discharge (GCD) cycle, the morphology of the surface graphite is lamellar, while it is irregular granular shape and appeared at the grain boundary of LLZTO solid electrolyte after GCD cycle. Raman and XPS results shows that a LiC 6 compound is formed after GCD cycle, which locally form LiC 6 /LLZTO/LiC 6 microbatteries, where Li + can spontaneously diffuse in the in-situ lithiated graphite layer, thereby enhancing the electrochemical performance of the battery.
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高影响因子
ACS Applied Energy Materials
·
2021
·
IF 6.024
Shengdong Tao,Jian Li,Lihua Wang,Weiguo Huang,Minchao Zhang,Zhexi Chi,Shuohan Wang,Yongzhi Chen,Lei Shang
Development of an active filler with a large specific surface area, fast ion conductivity phase, special shape, and high electrochemical stability is a critical issue for prominent performance composite solid-state electrolytes (CSEs) in solid-state lithium-ion batteries. Here, we report large specific surface area and coral-like cubic Li7La3Zr2O12 (LLZO) that was synthesized via a metal–organic framework (MOF) at a low calcination temperature (1000 °C). As active fillers, the coral-like cubic LLZO and lithium oxalyldifluroborate (LiODFB) uniformly distributed in a poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) matrix provide an interconnected Li-ion transport channel in CSE, which manifests outstanding properties such as a favorable electrochemical stability window (of 4.85 V vs Li/Li+), high ionic conductivity (1.65 × 10–4 S cm–1, 20 °C), and superior interface compatibility with lithium metal. The assembled LiFePO4/CSE/Li and LiCoO2/CSE/Li cells convey predominate performance and initial specific capacities of 135.0 and 135.9 mA h g–1 at 0.5 C, with capacity retention values of 83.51% after 500 cycles and 93.90% after 200 cycles. The coral-like LLZO with a large specific area reduces polymer crystallinity and provides a large phase interface in CSE through interaction of LLZO with LiODFB and PVDF-HFP. The results suggest that coral-like LLZO prepared by MOFs is a promising filler in CSEs for solid-state lithium-ion batteries.
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高影响因子
SOLID STATE IONICS
·
2025
·
IF 3.3
Shihao Fu,Pingmei Li,Shiyu Yu,Yang Hu,Yibo Liu,Daming Chen,Yaqing Wei,Yuanxun Li,Yong Chen
The garnet-type Li 7 La 3 Zr 2 O 12 (LLZO) has garnered significant attention due to its superior thermal stability and broad electrochemical window. However, LLZO exhibits instability at room temperature and readily transforms from a cubic phase ( c -LLZO) to a tetragonal phase ( t -LLZO), resulting in issues such as low ionic conductivity. Herein, the effect of Ga doping on LLZO is investigated. Combined with SEM, activation energy, ionic conductivity and XRD refinement, the results demonstrate that Li 7-3x Ga x La 3 Zr 2 O 12 exhibits better properties when x = 0.25. Solid-state nuclear magnetic resonance (SSNMR) showed that Ga0.25-LLZO was favorable for promoting Li + transport. Moreover, Li| [email protected] |Li symmetric cells exhibit lower interfacial specific impedance (IASR) and higher critical current density (CCD) than both Li|Ag@Ga0-LLZO|Li and Li| [email protected] |Li and was stabilized at 0.15 mA/cm 2 for 1300 h of stable cycling. In addition, the all-solid-state battery Li| [email protected] |LFP was cycled at 0.2C for 100 cycles with 82 % capacity retention, demonstrating its promising application in lithium batteries.
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高影响因子
Nanoscale
·
2021
·Vol. 13
·期 16
·7822-7830
·
IF 7.79
Yuwan Dong,Panzhe Su,Guanjie He,Huiling Zhao,Ying Bai
With high theoretical capacity and tap density, LiCoO2 (LCO) cathode has been extensively utilized in lithium-ion batteries (LIBs) for energy storage devices. However, the bottleneck of structural and interfacial instabilities upon cycling severely restricts its practical application at high cut-off voltage. From another perspective, the compatibility between the electrode and electrolyte is highly valued in the development of all-solid-state batteries. Herein, we construct a compatible interface between Li7La3Zr2O12 (LLZO) and LCO through a facile surface modification strategy, which significantly improves the cycling stability of LCO at a high cut-off voltage of 4.5 V. Characterization results demonstrate that the LCO@1.0 LLZO sample delivers a desirable capacity retention of 76.8% even after 1000 cycles at 3.0–4.5 V with the current density of 1 C (1 C = 274 mA g−1). Further investigation indicates that the LLZO modification layer could protect the LCO electrode through effectively alleviating the side reactions, which not only facilitates the Li+ transportation at the interface but also mitigates the bulk structure degradation. Moreover, it is also established that a small amount of La and Zr ions could gradiently migrate into the surface lattice of LCO to generate a thin layer of the surface solid solution Li–Co–La–Zr–O. Thus formed pinning region between surface modified LLZO and LCO cathode could contribute both to their mechanical compatibility and Li+ kinetics behavior upon repeated cycling. This work not only provides a strategy in broadening the operation potential and extracting higher capacity of LCO but also sheds light on constructing compatible interfaces in LIBs, especially for all-solid-state energy storage and conversion devices.
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PubMed
高影响因子
SOLID STATE IONICS
·
2022
·
IF 3.699
Tianxiang Ning,Yanzhi Zhang,Qian Zhang,Xuefeng Shen,Yinyi Luo,Taoyong Liu,Piao Liu,Zhiwei Luo,Anxian Lu
In this study, Ta single-doped Li 6.4 La 3 Zr 1.4 Ta 0.6 O 12 (Ta 0.6 ) and a series of Ta, Sr co-doped Li 6.4+x La 3-x Sr x Zr 1.4 Ta 0.6 O 12 (Ta 0.6 Sr x , x = 0.1, 0.2, 0.3, and 0.4) electrolytes are synthesized via a two-step process. The XRD result reveals that all samples have a pure cubic phase, which indicates that Ta 5+ and Sr 2+ can enter the lattice of LLZO and stabilize the cubic phase. The SEM images exhibit that all samples have a dense microstructure and tight grain boundary without obvious holes. The excellent properties are achieved when the doping amount of Sr reaches 0.2 mol. Among all designed samples, the Ta 0.6 Sr 0.2 has the highest Li + conductivity and relative density of 8.54 × 10 −4 S cm −1 and 98.79%, respectively, as well as the lowest activation energy roughly 0.302 eV. Additionally, the symmetrical cell's galvanostatic cycling data show that it has excellent cycling performance and extremely low overpotentials even after 350 cycles, indicating that it can be successfully applied to next-generation all-solid-state lithium-ion batteries (ASSLIBs).
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高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Xiangping Feng,Lei Zhang,Chao Li,Ming Shen,Runguo Zheng,Zhiyuan Wang,Hongyu Sun,Yanguo Liu
Cubic phase Li 7 La 3 Zr 2 O 12 (LLZO) is a promising electrolyte material for all-solid-state rechargeable lithium-ion batteries. The homogeneous densification of the garnet solid electrolyte ceramic material is crucial for enhancing its ionic conductivity performance. Herein, an Al/Ta co-doped strategy is employed to stabilize the cubic phase structure of LLZO and is combined with a two-step sintering method to enhance densification, in order to investigate its effect on microstructure, ionic conductivity, and electrochemical properties . During the formation process, amorphous Li 2 O reacts with doped Al 2 O 3 to create a Li–Al–O liquid phase at the grain boundaries. Combined with two-step sintering to ensure that the desired material transformation is achieved, resulting in a dense microstructure and better mechanical properties. The solid electrolyte Li 6.4 Al 0.1 La 3 Zr 1.7 Ta 0.3 O 12 under two-step sintering (LLZATO-2) is successfully synthesized, delivering an ionic conductivity up to 7.33 × 10 −4 S cm −1 at room temperature and an activation energy of 0.22 eV. This work also highlights the critical role of co-doping combined with two-step sintering in preparing well-performing solid-state electrolytes and all-solid-state lithium-ion batteries.
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高影响因子
Sustainable Energy & Fuels
·
2020
·Vol. 4
·期 7
·3500-3510
·
IF 5.503
N. Angulakshmi,R. Baby Dhanalakshmi,Paulina Półrolniczak,Mariusz Walkowiak,Pengfei Xie,Xiaohui Tian,Yingke Zhou,A. Manuel Stephan
Controlling the shuttling of lithium polysulphides (LiPS) to enhance the utilization of elemental sulfur has been considered as an important issue to improve the energy density and coulombic efficiency of lithium–sulfur batteries. The present work is aimed at demonstrating a simple preparation of a bi-functional trilayer membrane by coating Li7La3Zr2O12 and activated carbon on either side of the commercial membrane (Celgard 2320). The coated membrane was characterized by ionic conductivity, thermogravimetric and contact angle analyses. In the trilayer membrane, each component acts for a particular purpose: the activated carbon not only acts as a barrier for the migration of polysulfide but also provides additional pathways for electron transport for the insulating sulphur cathode, while the porous Celgard separator facilitates the migration of lithium ion, and the Li7La3Zr2O12 not only promotes the lithium ion migration by percolation but also prevents polysulfide shuttling via the electrostatic repulsive force. The coated membrane offered higher ionic conductivity and thermal stability compared to the uncoated one. The lithium–sulfur battery with the coated separator delivered higher specific discharge capacity than the uncoated separator. XPS studies revealed the absence of polysulfide deposition on the lithium metal surface after the charge–discharge cycling, which further confirms the suppression of polysulfide shuttling by permselective membranes.
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高影响因子
ELECTROCHIMICA ACTA
·
2018
·
IF 5.116
Yanhua Zhang,Jiadong Deng,Dongwei Hu,Fei Chen,Qiang Shen,Lianmeng Zhang,Shijie Dong
The Li + concentration and Li + transport channel size of garnet-type solid electrolyte Li 7 La 3 Zr 2 O 12 are the two key factors associated with the improvement of Li ionic conductivity . Through precise control of the Li + concentration and the Li + transport channel size by Ta-doping (Li 7-X La 3 Zr 2-X Ta X O 12 , X = 0.2–1.0), synergistic regulation of the two factors is achieved. Results show that the optimum Li + concentration seems to be at about 6.31 where the Li + occupancy in LiO 6 is high and the Li + arrangement in LiO 4 is disordering. With the Li + concentration higher than 6.31, the occupancy in LiO 4 sites remains constant but the Li + arrangement in LiO 4 becomes more and more ordering. At higher Li + concentration of 6.52, Li + arrangement becomes certain of ordering which should have reduced the grain conductivity, however, the grain conductivity is still as high as 9.84 × 10 −4 S cm −1 . This indicates that LLZO with this Li + concentration have favorable Li + transport channel size. The optimum Li + transport channel size is about 12.95 ± 0.01 Å. At Li + concentration of 6.31, the proper Li + concentration is the main factor for the high grain ionic conductivity of 10.1 × 10 −4 S cm −1 . While at Li + concentration of 6.52, the suitable Li + transport channel size is the main factor for the high grain ionic conductivity. In conclusion, the high grain ionic conductivity at Li + concentration of 6.31–6.52 is due to the synergistic regulation of Li + concentration and Li + transport channel size.
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高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Yanhua Zhang,Xinglong Gao,Zijun Tang,Yuhang Mei,Xing Xiang,Jiadong Deng
The lithium dendrites growth in Li 7 La 3 Zr 2 O 12 (LLZO) solid electrolytes has severely restricted the development of all-solid-state lithium batteries. Herein, two different dynamic properties interlayers of electronically conductive Al and an electronically non-conductive Al 2 O 3 are constructed at the Li/LLZO interface, and the lithium dendrite growth mechanism is explored. Results show that battery with Al interlayer occur internal short circuit in 95 cycles, while the battery with annealed Al 2 O 3 interlayer has good cycle stability of 1000 cycles with polarization voltage below 0.1 V. Besides, dendritic lithium dendrites can be clearly observed at the LLZO grain boundaries of battery with Al interlayer. Raman and XPS results show that the Al 2 O 3 interlayer reacts with Li + during the charge and discharge process to form a Li-Al-O compound which is Li + conductive. It is concluded that the lithium dendrite inhibition mechanism of the Li-Al-O compound interlayer is that it can promote the Li + conduction from LLZO to lithium anode to undergo a lithium deposition reaction, and prevents electrons from conducting to LLZO and combine with Li + to occur lithium dendrite growth. While for the Al interlayer, electrons can reach LLZO through the interlayer to combine with Li + thus occurring the lithium dendritic growth.
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高影响因子