| 1. |
- Chen, Yaqi, et al.
(författare)
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Two Birds with One Stone: Using Indium Oxide Surficial Modification to Tune Inner Helmholtz Plane and Regulate Nucleation for Dendrite-free Lithium Anode
- 2022
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Ingår i: Small Methods. - : Wiley. - 2366-9608. ; 6:5
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Tidskriftsartikel (refereegranskat)abstract
- Lithium metal has been considered as the most promising anode material due to its distinguished specific capacity of 3860 mAh g–1 and the lowest reduction potential of -3.04 V versus the Standard Hydrogen Electrode. However, the practicalization of Li-metal batteries (LMBs) is still challenged by the dendritic growth of Li during cycling, which is governed by the surface properties of the electrodepositing substrate. Herein, a surface modification with indium oxide on the copper current collector via magnetron sputtering, which can be spontaneously lithiated to form a composite of lithium indium oxide and Li-In alloy, is proposed. Thus, the growth of Li dendrites is effectively suppressed via regulating the inner Helmholtz plane modified with LiInO2 to foster the desolvation of Li-ion and induce the nucleation of Li-metal in two-dimensions through electro-crystallization with Li-In alloy. Using the In2O3 modification, the Li-metal anode exhibits outstanding cyclic stability, and LMBs with lithium cobalt oxide cathode present excellent capacity retention (above 80% over 600 cycles). Enlightening, the scalable magnetron sputtering method reported here paves a novel way to accelerate the practical application of the Li anode in LMBs to pursue higher energy density.
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| 2. |
- Liu, Yangyang, et al.
(författare)
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Electro-Chemo-Mechanical Modeling of Artificial Solid Electrolyte Interphase to Enable Uniform Electrodeposition of Lithium Metal Anodes
- 2022
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Ingår i: Advanced Energy Materials. - : Wiley. - 1614-6840 .- 1614-6832. ; 12:9
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Tidskriftsartikel (refereegranskat)abstract
- Nonuniform electrodeposition of lithium during charging processes is the key issue hindering development of rechargeable Li metal batteries. This deposition process is largely controlled by the solid electrolyte interphase (SEI) on the metal surface and the design of artificial SEIs is an essential pathway to regulate electrodeposition of Li. In this work, an electro-chemo-mechanical model is built and implemented in a phase-field modelling to understand the correlation between the physical properties of artificial SEIs and deposition of Li. The results show that improving ionic conductivity of the SEI above a critical level can mitigate stress concentration and preferred deposition of Li. In addition, the mechanical strength of the SEI is found to also mitigate non-uniform deposition and influence electrochemical kinetics, with a Young's modulus around 4.0 GPa being a threshold value for even deposition of Li. By comparison of the results to experimental results for artificial SEIs it is clear that the most important direction for future work is to improve the ionic conductivity without compromising mechanical strength. In addition, the findings and methodology presented here not only provide detailed guidelines for design of artificial SEI on Li-metal anodes but also pave the way to explore strategies for regulating deposition of other metal anodes.
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| 3. |
- Xu, Xieyu, et al.
(författare)
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Diffusion Limited Current Density: A Watershed in Electrodeposition of Lithium Metal Anode
- 2022
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Ingår i: Advanced Energy Materials. - : Wiley. - 1614-6840 .- 1614-6832. ; 12:19
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Tidskriftsartikel (refereegranskat)abstract
- Lithium metal is considered to be a promising anode material for high-energy-density rechargeable batteries because of its high theoretical capacity and low reduction potential. Nevertheless, the practical application of Li anodes is challenged by poor cyclic performance and potential safety hazards, which are attributed to non-uniform electrodeposition of Li metal during charging. Herein, diffusion limited current density (DLCD), one of the critical fundamental parameters that govern the electrochemical reaction process, is investigated as the threshold of current density for electrodeposition of Li. The visualization of the concentration field and distribution of Faradic current density reveal how uniform electrodeposition of Li metal anodes can be obtained when the applied current density is below the DLCD of the related electrochemical system. Moreover, the electrodeposition of Li metal within broken solid electrolyte interphases preferentially occurs at the crack spots that are caused by the non-uniform electrodeposition of Li metal. This post-electrodeposition leads to more consumption of active Li when the applied current density is greater than the DLCD. Therefore, lowering the applied current density or increasing the DLCD are proposed as directions for developing advanced strategies to realize uniform electrodeposition of Li metal and stable interfaces, aiming to accelerate the practical application of state-of-the-art Li metal batteries.
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| 4. |
- Xu, Xieyu, et al.
(författare)
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Electro-Chemo-Mechanical Failure of Solid Electrolytes Induced by Growth of Internal Lithium Filaments
- 2022
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Ingår i: Advanced Materials. - : Wiley. - 0935-9648 .- 1521-4095. ; 34:49
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Tidskriftsartikel (refereegranskat)abstract
- Growth of lithium (Li) filaments within solid electrolytes, leading to mechanical degradation of the electrolyte and even short circuit of the cell under high current density, is a great barrier to commercialization of solid-state Li-metal batteries. Understanding of this electro-chemo-mechanical phenomenon is hindered by the challenge of tracking local fields inside the solid electrolyte. Here, a multiphysics simulation aiming to investigate evolution of the mechanical failure of the solid electrolyte induced by the internal growth of Li is reported. Visualization of local stress, damage, and crack propagation within the solid electrolyte enables examination of factors dominating the degradation process, including the geometry, number, and size of Li filaments and voids in the electrolyte. Relative damage induced by locally high stress is found to preferentially occur in the region of the electrolyte/Li interface having great fluctuations. A high number density of Li filaments or voids triggers integration of damage and crack networks by enhanced propagation. This model is built on coupling of mechanical and electrochemical processes for internal plating of Li, revealing evolution of multiphysical fields that can barely be captured by the state-of-the-art experimental techniques. Understanding mechanical degradation of solid electrolytes with the presence of Li filaments paves the way to design advanced solid electrolytes for future solid-state Li-metal batteries.
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