首页|固体电解质界面层锂合金相的高通量筛选与界面离子输运研究

固体电解质界面层锂合金相的高通量筛选与界面离子输运研究

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  • 国家科技期刊平台
  • NETL
  • NSTL
  • 万方数据
固体电解质界面层(SEI)对锂离子电池的电化学性能有着重要影响,理想的SEI层应同时具备良好的电子绝缘性、较高的离子电导率,以及一定的界面机械强度来承受锂沉积/剥离行为所伴随的体积变化和抑制锂枝晶形成.构筑LiF基人工SEI层已被证明是保护固态锂离子电池负极界面的有效策略.本工作通过材料数据库挖掘技术、高通量第一性原理计算和从头算分子动力学模拟对若干锂合金进行相图计算、扩散能垒计算,以评估其热力学稳定性和锂离子扩散能力,最终筛选出27种可用于LiF基人工SEI层锂离子导电相的锂合金材料.同时,对若干锂合金的晶体结构-扩散性质进行构效关系分析发现,锂合金晶体结构类型对锂离子扩散能力的影响比其元素组分更加显著,即(I4)3d和Fm(3)m族群结构的锂合金具备非常优异的锂离子输运性能,而Pm(3)m和F4(3)m族群结构的锂合金扩散通道狭窄,锂离子输运性能差.此外,本计算工作发现锂离子在LiF晶体中扩散迁移是极其困难的,而在LiF晶界和LiF/LiM合金界面迁移扩散阻力极小,藉此获得人工SEI界面层中锂离子输运的物理图像.
High-Throughput Screening Lithium Alloy Phases and Investigation of Ion Transport for Solid Electrolyte Interphase Layer
Solid electrolyte interphase(SEI)layers derived from the side reactions between Li metal anode and electrolyte,have great impacts on the electrochemical performance of lithium batteries.In solid-state batteries,SEI layers are also required as the electrical insulators but an ionic conductors,and the mechanical reinforcements for withstanding volume change and suppressing dendritic growth in Li metal anode.Introducing LiF substrates into SEI layers can significantly reduce the electron tunneling ability from Li anode to SEI layer,meanwhile providing the excellent interfacial mechanical strength.However,LiF has a very high energy barrier for ion diffusion,hindering the rapid lithium ion diffusion from SEI layer to lithium anode.Therefore,it is necessary to introduce lithium alloy phases with higher ionic conductivity into the LiF matrix to provide sufficient ion diffusion channels.By the data mining technology,high-throughput first-principle calculation and ab-initio molecular dynamics simulations,this work performed phase diagram and ion diffusion energy barrier calculations to evaluate the thermodynamic stabilities and lithium diffusion abilities of several lithium alloys.27 lithium alloys that can be used as Li-ion conducting phases in the LiF-based artificial SEI layers are screened.Meanwhile,the structure-function relationship analysis of lithium alloys uncovers that the crystal structure type of lithium alloys has more significant impacts on lithium ion diffusion than alloy elements,that is,lithium alloy structures with the space group of(I4)3d and Fm(3)m have very excellent lithium ion transport performance,while the diffusion channels of lithium alloy structures with the space group of Pm(3)m and F4(3)m are narrow,leading to the poor lithium ion transport performance.In addition,this work uncovers a physical image of lithium ion transport in artificial SEI interface,that is,lithium ion diffusion in LiF crystal bulk is quite difficult,while the diffusion resistance at LiF grain boundaries and LiF/LiM alloy interfaces is small.

Solid-state batteryArtificial SEI interfaceLithium alloyFirst-principle calculationInterfacial ion diffusion

窦智、段慧宇、林奕希、夏颖慧、郑明波、许真铭

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南京航空航天大学材料科学与技术学院,江苏省高效电化学储能技术重点实验室,南京 210016

固态电池 人工SEI界面 锂合金 第一性原理计算 界面离子扩散

国家自然科学基金中央高校基本科研业务费专项中央高校基本科研业务费专项国家超级计算天津中心的中国材料基因工程高通量计算平台开放研究基金

22209074NS2022059NS2021039CNMGE202312

2024

10.3866/PKU.WHXB202305039

物理化学学报
中国化学会

物理化学学报

CSTPCD北大核心
影响因子：0.951
ISSN：1000-6818
年,卷(期)：2024.40(3)
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