In situ formation of stable solid electrolyte interphase with high ionic conductivity for long lifespan all-solid-state lithium metal batteries
In situ formation of stable solid electrolyte interphase with high ionic conductivity for long lifespan all-solid-state lithium metal batteries
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DOI：
10.1016/j.ensm.2023.02.009
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发表时间：
2023-02-09
影响因子：
20.4
通讯作者：
Shahbazian-Yassar, Reza
中科院分区：
文献类型：
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作者：
Jabbari, Vahid;Yurkiv, Vitaliy;Shahbazian-Yassar, Reza
由于超高的Li还原性以及较差的界面稳定性或离子电导率，锂（Li）金属和聚合物电解质的界面不可避免地发生寄生反应。这会导致锂金属电池（LMB）的容量显着损失和寿命缩短。在此，我们通过掺入磷腈分子，在锂金属和聚环氧乙烷（PEO）电解质的界面设计了稳定的固体电解质中间相（SEI）层。与未改性的 SPE 相比，磷腈固体聚合物电解质 (P-SPE) 对锂金属负极表现出明显更高的长期稳定性。使用低温透射电子显微镜 (cryo-TEM) 和 X 射线光子能谱 (XPS)，在 SEI 层中鉴定出 Li3N、LiF、Li3P 和 Li3PO4 纳米晶体。采用 P-SPE 的 Li|Li 电池在 0.2 mA cm-2 下循环 1800 次。采用 P-SPE 的 Li||LFP 电池在 1C 和 2C 充电/放电速率下的比容量分别为 -150 mAh g- 1 和 -120 mAh g- 1，在 500 次和 1000 次循环后容量保持率分别高达 80%。通过密度函数理论 (DFT) 和从头算分子动力学 (AIMD) 计算进一步研究了磷腈改性 SEI 在提高电化学性能方面的关键作用。这项研究为设计稳定且离子导电的锂聚合物电解质界面以实现长寿命 LMB 提供了一种有前景的方法。
Parasitic reactions inevitably occur at the interface of lithium (Li) metal and polymer electrolytes due to ultrahigh Li reducibility coupled with poor interfacial stability or ionic conductivity. This leads to significant capacity loss and inferior lifespan of Li metal batteries (LMBs). Herein, we engineered a stable solid electrolyte interphase (SEI) layer at the interface of Li metal and polyethylene oxide (PEO) electrolyte via incorporation of phosphazene molecules. The phosphazene-solid polymer electrolyte (P-SPE) shows a significantly higher longterm stability against Li metal anode when compared with non-modified SPE. Using cryogenic transmission electron microscopy (cryo-TEM) and X-ray photon spectroscopy (XPS), Li3N, LiF, Li3P and Li3PO4 nanocrystals were identified in the SEI layer. The Li|Li cell with P-SPE cycle for 1800 cycles at 0.2 mA cm-2. The Li||LFP cells with P-SPE deliver a specific capacity of -150 mAh g- 1 and -120 mAh g- 1 at 1C and 2C charge/discharge rates, respectively, with up to 80% capacity retention after 500 and 1000 cycles, respectively. Critical role of phosphazene-modified SEI in improving electrochemical performance is further investigated by density function theory (DFT) and ab-initio molecular dynamic (AIMD) calculations. This study offers a promising approach for engineering a stable and ion-conductive Li|polymer electrolyte interface for long lifespan LMBs.