| 1. |
- Liu, Qiao, et al.
(författare)
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Enhanced ionic conductivity and interface stability of hybrid solid-state polymer electrolyte for rechargeable lithium metal batteries
- 2019
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Ingår i: Energy Storage Materials. - : Elsevier BV. - 2405-8297. ; 23, s. 105-111
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Tidskriftsartikel (refereegranskat)abstract
- Compared to conventional organic liquid electrolyte, solid-state polymer electrolytes are extensively considered as an alternative candidate for next generation high-energy batteries because of their high safety, non-leakage and electrochemical stability with the metallic lithium (Li) anode. However, solid-state polymer electrolytes generally show low ionic conductivity and high interfacial impedance to electrodes. Here we report a hybrid solid-state electrolyte, presenting an ultra-high ionic conductivity of 3.27 mS cm −1 at room temperature, a wide electrochemical stability window of 4.9 V, and non-flammability. This electrolyte consists of a polymer blend matrix (polyethylene oxide and poly (vinylidene fluoride-co-hexafluoropropylene)), Li + conductive ceramic filler (Li 1.5 Al 0.5 Ge 1.5 (PO 4 ) 3 ) and a solvate ionic liquid (LiFSI in tetra ethylene glycol dimethyl ether, 1:1 in molar ratio) as plasticizer. The introduction of the solvate ionic liquid to the solid-state electrolyte not only improves its ionic conductivity but also remarkably enhances the stability of the interface with Li anode. When applied in Li metal batteries, a Li|Li symmetric cell can operate stably over 800 h with a minimal polarization of 25 mV and a full Li|LiFePO 4 cell delivers a high specific capacity of 158 mAh g −1 after 100 cycles at room temperature.
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| 2. |
- Liu, Yangyang, et al.
(författare)
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Insight into the Critical Role of Exchange Current Density on Electrodeposition Behavior of Lithium Metal
- 2021
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Ingår i: Advanced Science. - : Wiley. - 2198-3844 .- 2198-3844. ; 8:5
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Tidskriftsartikel (refereegranskat)abstract
- Due to an ultrahigh theoretical specific capacity of 3860 mAh g−1, lithium (Li) is regarded as the ultimate anode for high-energy-density batteries. However, the practical application of Li metal anode is hindered by safety concerns and low Coulombic efficiency both of which are resulted fromunavoidable dendrite growth during electrodeposition. This study focuses on a critical parameter for electrodeposition, the exchange current density, which has attracted only little attention in research on Li metal batteries. A phase-field model is presented to show the effect of exchange current density on electrodeposition behavior of Li. The results show that a uniform distribution of cathodic current density, hence uniform electrodeposition, on electrode is obtained with lower exchange current density. Furthermore, it is demonstrated that lower exchange current density contributes to form a larger critical radius of nucleation in the initial electrocrystallization that results in a dense deposition of Li, which is a foundation for improved Coulombic efficiency and dendrite-free morphology. The findings not only pave the way to practical rechargeable Li metal batteries but can also be translated to the design of stable metal anodes, e.g., for sodium (Na), magnesium (Mg), and zinc (Zn) batteries.
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