Green Energy & Environment
·
2023
·
IF 13.3
Rui Zhang,Biao Chen,Yuhan Ma,Yue Li,Junwei Sha,Liying Ma,Chunsheng Shi,Naiqin Zhao
Solid polymer electrolytes (SPEs) are highly promising for realizing high-capacity, low-cost, and safe Li metal batteries. However, the Li dendritic growth and side reactions between Li and SPEs also plague these systems. Herein, a fluorinated lithium salt coating (FC) with organic-inorganic gradient and soft–rigid feature is introduced on Li surface as an artificial protective layer by the in-situ reaction between Li metal and fluorinated carboxylic acid. The FC layer can improve the interface stability and wettability between Li and SPEs, assist the transport of Li ions, and guide Li nucleation, contributing to a dendrite-free Li deposition and long-lifespan Li metal batteries. The symmetric cell with FC-Li anodes exhibits a high areal capacity of 1 mAh cm −2 at 0.5 mA cm −2 , and an ultra-long lifespan of 2000 h at a current density of 0.1 mA cm −2 . Moreover, the full cell paired with the LiFePO 4 cathode exhibits improved cycling stability, remaining 83.7% capacity after 500 cycles at 1 C. When matching with the S cathode, the FC layer can prevent the shuttle effect, contributing to stable and high-capacity Li–S battery. This work provided a promising way for the construction of stable all-solid-state lithium metal batteries with prolonged lifespan.
研究领域:
材料科学
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电化学
·
电池技术
✓ 已验证
产品关联
DOI
高影响因子
Nature Catalysis
·
2022
·Vol. 5
·期 3
·193-201
·
IF 40.706
Cao Deqing,Shen Xiaoxiao,Wang Aiping,Yu Fengjiao,Wu Yuping,Shi Siqi,Freunberger Stefan A.,Chen Yuhui
Redox mediators could catalyse otherwise slow and energy-inefficient cycling of Li–S and Li–O 2 batteries by shuttling electrons or holes between the electrode and the solid insulating storage materials. For mediators to work efficiently they need to oxidize the solid with fast kinetics but with the lowest possible overpotential. However, the dependence of kinetics and overpotential is unclear, which hinders informed improvement. Here, we find that when the redox potentials of mediators are tuned via, for example, Li + concentration in the electrolyte, they exhibit distinct threshold potentials, where the kinetics accelerate several-fold within a range as small as 10 mV. This phenomenon is independent of types of mediator and electrolyte. The acceleration originates from the overpotentials required to activate fast Li + /e − extraction and the following chemical step at specific abundant surface facets. Efficient redox catalysis at insulating solids therefore requires careful consideration of the surface conditions of the storage materials and electrolyte-dependent redox potentials, which may be tuned by salt concentrations or solvents.
研究领域:
电化学
·
电池技术
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材料科学
✓ 已验证
DOI
高影响因子
ACS Nano
·
2020
·
IF 14.588
Feng Ma,Yangyang Wan,Xiaoming Wang,Xinchao Wang,Jiashun Liang,Zhengpei Miao,Tanyuan Wang,Cheng Ma,Gang Lu,Jiantao Han,Yunhui Huang,Qing Li
The sluggish kinetics of lithium polysulfides (LiPS) transformation is recognized as the main obstacle against the practical applications of the lithium–sulfur (Li–S) battery. Inspired by molybdoenzymes in biological catalysis with stable Mo–S bonds, porous Mo–N–C nanosheets with atomically dispersed Mo–N2/C sites are developed as a S cathode to boost the LiPS adsorption and conversion for Li–S batteries. Thanks to its high intrinsic activity and the Mo–N2/C coordination structure, the rate capability and cycling stability of S/Mo–N–C are greatly improved compared with S/N–C due to the accelerated kinetics and suppressed shuttle effect. The S/Mo–N–C delivers a high reversible capacity of 743.9 mAh g–1 at 5 C rate and an extremely low capacity decay rate of 0.018% per cycle after 550 cycles at 2 C rate, outperforming most of the reported cathode materials. Density functional theory calculations suggest that the Mo–N2/C sites can bifunctionally lower the activation energy for Li2S4 to Li2S conversion and the decomposition barrier of Li2S, accounting for its inherently high activity toward LiPS transformation.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry A
·
2019
·Vol. 7
·期 19
·12214-12224
·
IF 10.733
Yuanzhou Yao,Xiaohui Zhao,Amir Abdul Razzaq,Yuting Gu,Xietao Yuan,Rahim Shah,Yuebin Lian,Jinxuan Lei,Qiaoqiao Mu,Yong Ma,Yang Peng,Zhao Deng,Zhongfan Liu
The passivation of lithium metal anodes to mitigate an unstable solid electrolyte interface and parasitic dendrite growth is the key premise for their successful implementation in lithium metal batteries. Herein, aiming to simultaneously reduce the interfacial resistance and to suppress lithium dendrites, we coated lithium metal anodes with two-dimensional (2D) rGO layers prepared via a solvent-evaporation-assisted self-assembly. Upon lithiation/delithiation, the rGO coating cracked into mosaic-like flakes, in between which the interconnected gaps served as the passage for uniform lithium plating/stripping. Half cells composed of a sandwich Cu/Li/rGO electrode vs. Cu foils revealed much improved Li usage and coulombic efficiencies. Through ex situ SEM imaging and XPS depth profiling, a comprehensive view of Li intercalation, deposition, and dendrite suppression on the rGO coating was obtained. As a result of the improved kinetics of Li transportation, excellent electrochemical performances were demonstrated in symmetric gLi‖gLi cells with a stabilized overpotential of only 87.9 mV at 5 mA cm−2 over 600 cycles, and in Li–S batteries with a stabilized capacity of 1200 mA h g−1 at 1C near 1000 cycles.
研究领域:
材料科学
·
电化学
·
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）