In Situ Monitoring of Lithium Metal Anodes and Their Solid Electrolyte Interphases by Transmission Electron Microscopy

Abstract

Lithium (Li) metal anodes (LMAs) are considered to be the holy grail of electrodes to enable advanced battery chemistry for energy‐intensive applications. However, the formation of Li dendrites and their intricate interplay with the solid electrolyte interphase (SEI) remain unclear to date. Herein, a simple yet efficient methodology for in situ transmission electron microscopy (TEM) observation is reported, and the relationship between the SEI chemistry and the morphology of LMAs is unraveled by a combination of TEM imaging and selected area electron diffraction analysis in an unprecedented way. The authors find that the coexistence of LiF and Li3N in the SEI layer helps realize dendrite‐free Li deposition and directly visualize the deposition–dissolution behavior of individual Li deposits with different microstructures. The approach should be applicable to scrutinize a broad range of interfacial reactions in nonvolatile electrolytes (e.g., ionic liquid, glass‐, and ceramic‐based electrolytes) relevant to future energy storage devices, including magnesium secondary batteries.

Reclaiming Inactive Lithium with a Triiodide/Iodide Redox Couple for Practical Lithium Metal Batteries

“…After soaking the fully delithiated NCM523 cathode into the above solution, the peaks corresponding to I 3 À appear, indicating the oxidization of I À into I 3 À through Eq. (5). Similar evidence can also be detected from the results of X-ray diffraction (XRD,Figure 2b).…”

Reclaiming Inactive Lithium with a Triiodide/Iodide Redox Couple for Practical Lithium Metal Batteries

“…[3] The dilemma of the historic failure of LMBs results from serval reasons including Li dendrite growth, inactive Li (also known as dead Li)a ccumulation, and unstable solid electrolyte interphase (SEI). [4] Notably,S EI with uneven components and nanostructures is directly responsible for the growth of dendritic Li, [5] and Li dendrites with high tortuosity potentially promote the formation of inactive Li. [6] Principally, inactive Li formed in Li metal batteries comprises Li ions (Li + )i nt he hollowed-out SEI and metallic Li debris (Li 0 ) electrically isolated by SEI.…”

Recent advances of non-lithium metal anode materials for solid-state lithium-ion batteries

“…As new alloy anode materials for high energy density lithium-ion batteries, Bi and Sb can generate Li 3 Bi and Li 3 Sb in the electrode reaction process, which provides volume capacities of 3800 mA h cm À3 and 4420 mA h cm À3 , respectively, showing the same performance that is expected in solid-state lithium-ion batteries. 33 Many articles focus on the problems of lithium metal as an anode material in solid-state batteries, [34][35][36][37] and few articles systematically comment on the application of non-lithium metal anode materials in solid-state lithium-ion batteries. Here, we focus on reviewing the research progress of lithium-free anode materials in solid-state batteries.…”

“…Many articles focus on the problems of lithium metal as an anode material in solid-state batteries, 34–37 and few articles systematically comment on the application of non-lithium metal anode materials in solid-state lithium-ion batteries. Here, we focus on reviewing the research progress of lithium-free anode materials in solid-state batteries.…”