SOLID STATE IONICS
·
2020
·
IF 3.107
Xuefeng Shen,Qian Zhang,Tianxiang Ning,Jianlei Liu,Taoyong Liu,Zhiwei Luo,Yao He,Chunchun Qin,Anxian Lu
Garnet solid electrolyte is the most promising candidate among inorganic solid electrolytes due to its wide potential window, good compatibility and high safety. In this work, a dual doping strategy is offered for the development of garnet-type electrolytes with high ionic conductivity . Te 6+ is introduced into the Zr sites to stabilize the high-ionic conductivity cubic phase. Simultaneously, Sr 2+ enter the La sites to achieve a fine-tuning of the Li + concentration by charge compensation, acting as a sintering agent of Te 6+ /Sr 2+ doped electrolytes. The structure, chemical composition and ionic conductivity of Li 7 − 2 y + x La 3 − x Sr x Zr 2 − y Te y O 12 ( x = 0–0.25, and y = 0.35) electrolytes are systematically investigated by X-ray diffraction, Raman spectroscopy , scanning electron microscope , Energy Dispersive X-ray Spectroscopy, Inductively Coupled Plasma-Optical Emission Spectrometry and Alternating Current impedance. The results show that the optimal amount of Sr 2+ substitution helps to reduce the total resistance by promoting the growth of grains and ceramic densification . Among the investigated compositions, the composition with Li 6.425 La 2.875 Sr 0.125 Zr 1.65 Te 0.35 O 12 exhibits excellent performance with relative density of 97.95%, conductivity of 4.27 × 10 −4 S cm −1 at 25 °C and activation energy of 0.30 eV. The assembled Li/Li 6.425 La 2.875 Sr 0.125 Zr 1.65 Te 0.35 O 12 /Li symmetrical batteries are cycled galvanostatically under different current densities. The results show that the symmetrical battery can achieve good cyclic stability, good Li + stripping and plating process and low overpotential.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
Catalysts
·
2023
·Vol. 13
·期 6
·931
·
IF 3.9
Junling Wei,Li Xu,Lihua Hu,Tiejun Wang,Yufei Ma
Hydrogen evolution reaction (HER) is a topic of great interest due to its efficient hydrogen production properties, which can address the increasing demand for clean and sustainable energy sources. On the other hand, molybdenum carbide (MoC) has been widely studied due to its noble metal-like surface electronic properties. In the HER process, it is crucial to regulate the Mo−H bonding energy effectively and increase the electron transfer rate on the MoC catalyst surface in a rational manner. In this study, we introduce highly electronegative nitrogen and non-noble transition metal atoms (Cu or Co) into the molybdenum carbide crystal lattice (N−M−MoC, M: Cu, or Co), which leads to a dual—doping effect. This effect results in the rearrangement of the electronic configuration on the catalyst surface and the enrichment of electrons around Mo atom, leading to an optimization in the Mo−H bonding energy. Moreover, the unique two-dimensional nano-sheet structure of the N−M−MoC materials further promotes the electron transfer and exposure of active sites. Benefiting from the above, the HER performance of the N−M−MoC is significantly improved. Among them, N−Cu−MoC exhibits the lowest overpotential (η10= 158 mV) and highest stability (about 30 h) in alkaline solutions.Keywords:dual-doping;heteroatoms;molybdenum carbide;hydrogen evolution reaction;surface electronic structure
研究领域:
材料科学
·
催化化学
·
能源科学
✓ 已验证
DOI
高影响因子
Small
·
2024
·
IF 13
Shuxiong Wang,Xiaoxin Zhang,Yu Chen,Fan Fan,Chang Jiang,Yongkang Xiang,Xiao Xiao,Yuan Fang,Abdullah N. Alodhayb,Jianhui Li,Jijie Huang,Yifei Sun,Zhou Chen
Lowering the thermal expansion coefficient (TEC) and promoting the catalytic activity of cobalt-based perovskite air electrodes is crucial for efficient solid oxide cells (SOCs) devices. However, the co-achievement of both merits has usually been largely compromised in most scenarios. Herein, a dual-doping strategy to manipulate the properties of perovskite cobaltate electrocatalyst is reported in which a high valence element of Ta 5+ is incorporated into B-site to significantly suppress the dynamic reduction of Co 4+ species and reduces the TEC value from PrBaCo 2 O 5+δ (PBC, 17.8 × 10 ⁻6 K −1 ) to PrBaCo 1.96 Ta 0.04 O 5+δ (PBCT, 12.5 × 10⁻ 6 K −1 ) and suppresses the oxygen loss in SOCs operation condition, revealing the improved structural stability. Meanwhile, the Ca 2+ is doped into A-site of Ta-incorporated candidate, further decreasing the covalency of Co─O bonds and facilitating the formation of oxygen vacancies, benefiting the oxygen exchange kinetics and leading to a low polarization resistance of 0.026 Ω cm 2 (800 °C) in as-prepared PrBa 0.8 Ca 0.2 Co 1.96 Ta 0.04 O 5+δ (PBCCT) electrode. The cell with PBCTT demonstrates remarkable robustness during a 50 h thermal cycling test (25 cycles). Moreover, it delivers a high current density of 1.44 A cm⁻ 2 (1.6 V, 800 °C), as well as attractive durability over 100 h for pure CO 2 electrolysis.
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
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.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2022
·
IF 10.383
Min Xue,Mufan Cao,Chengyang Xu,Dewei Xiao,Xiaogang Zhang
Polymer-based materials with the incorporation of redox-active dopants serve as promising electrodes for Li-ion batteries but their use is restricted by the limited doping level and inevitable dissolution behavior of the dopants. Here, we proposed a conjugated polymer-based electrode with an assistant dopant to realize the reversible capacity contribution of a redox-active dopant. By employing phosphate anion (PO) as the assistant dopant to stable the polymer matrix, the reversible capacity was improved by introducing indigo carmine (IC) into the polymer electrode. Based on the real-time monitoring of the electrochemical quartz crystal microbalance toward the mass change, the charge storage behavior of the redox-active dopant IC was observed and the stabilizing effect of the assistant dopant PO was revealed. The modified electrode delivered an increased capacity of 191 mA h g–1, and the reversible capacity remained 56% higher than that of the PO-undoped electrode after 200 cycles. The dual-doping strategy with the assistant dopant and the redox-active dopant is used to develop advanced polymer-based electrodes for high-capacity and long-cycling batteries.
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
ADVANCED FUNCTIONAL MATERIALS
·
2025
·Vol. 35
·期 22
·2426053
·
IF 19
Qixiang Jia,Zhujun Yao,Jiayuan Xiang,Juntao Shi,Yan Zhou,Jianhao Huang,Hongliang Zhang,Xiaoxiao Zhang,Yefeng Yang,Jiangping Tu
Li 2 ZrCl 6 (LZC) solid electrolyte has been recognized as a promising candidate for all-solid-state batteries (ASSBs), owing to its remarkable compatibility with high-voltage cathodes and the cost advantage among halide electrolytes. However, the ionic conductivity of LZC (≈0.4 mS cm −1 ) requires enhancement. Herein, rare earth metal elements (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb, Y) have been doped into LZC, resulting in a doubling of the ionic conductivity. Moreover, Ta 5+ is utilized to further modulate the concentration of Li + to enhance the ionic conductivity and reduce the dosage of expensive rare-earth metal. Using the Li-Zr-Dy-Cl component as a case study, 16 types of Dy 3+ and Ta 5+ co-doped electrolytes have been synthesized and the optimal Li 2.1 Zr 0.8 Dy 0.15 Ta 0.05 Cl 6 (LZDTC) exhibits the ionic conductivity of 1.67 mS cm −1 . Three-dimensional Li-ion transport pathways in LZDTC has been revealed. The dual-substitution of Dy and Ta at Zr site changes length of Li-Cl bond and Li occupation, thereby reducing the resistance to Li + migration. ASSBs of Li-In/LGPS-LZDTC/NCM811 demonstrate a capacity of 117 mA h g −1 after 500 cycle at 0.5 C with a 74% retention rate, highlighting the effectiveness of the dual-doping strategy for creating superionic conductors for ASSBs.
研究领域:
材料科学
·
电化学
·
储能技术
·
固体离子学
·
电池技术
✓ 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）