scholarly journals Elucidating Interfacial Stability between Lithium Metal Anode and LiPON via In Situ Electron Microscopy

2020 ◽  
Author(s):  
Zachary Hood ◽  
Xi Chen ◽  
Robert Sacci ◽  
Gabriel Veith ◽  
Xiaoming Liu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Theoretical Calculations ◽  
Coulombic Efficiency ◽  
Interface Layer ◽  
Metal Anode ◽  
Lithium Metal Anode ◽  
In Situ Electron Microscopy ◽  
Electrochemical Window ◽  
The Stability

Abstract Li phosphorus oxynitride (LiPON) is one of a very few solid electrolytes that have demonstrated stability against Li metal, and performed extended cycling with high coulombic efficiency. However, theoretical calculations show that LiPON does react with Li metal. Here, we utilize in situ electron microscopy to directly observe the dynamic evolutions at the LiPON-Li interface upon contacting and under biasing at the nanometer scale. We reveal that a thin interface layer (~60nm) develops at the LiPON-Li interface upon contact. This interface layer is conductive and robust, serving as an effective passivation layer keeping the interface stable over time and under biasing up to 5 V. Our results explicate the excellent cyclability of LiPON and reconciles the existing debates regarding the stability of LiPON-Li interface. This work demonstrates that glassy solid-state electrolytes with a sufficient ionic conductivity, though may not have a perfect initial electrochemical window with Li metal, may excel in future applications for ASSBs.

scholarly journals Artificial dual solid-electrolyte interfaces based on in situ organothiol transformation in lithium sulfur battery

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Wei Guo ◽  
Wanying Zhang ◽  
Yubing Si ◽  
Donghai Wang ◽  
Yongzhu Fu ◽  
...  
Keyword(s):  
Solid Electrolyte ◽  
Interface Reaction ◽  
Interfacial Instability ◽  
Anode Surface ◽  
Commercial Application ◽  
Lithium Metal ◽  
Metal Anode ◽  
Lithium Metal Anode ◽  
Lithium Sulfur

AbstractThe interfacial instability of the lithium-metal anode and shuttling of lithium polysulfides in lithium-sulfur (Li-S) batteries hinder the commercial application. Herein, we report a bifunctional electrolyte additive, i.e., 1,3,5-benzenetrithiol (BTT), which is used to construct solid-electrolyte interfaces (SEIs) on both electrodes from in situ organothiol transformation. BTT reacts with lithium metal to form lithium 1,3,5-benzenetrithiolate depositing on the anode surface, enabling reversible lithium deposition/stripping. BTT also reacts with sulfur to form an oligomer/polymer SEI covering the cathode surface, reducing the dissolution and shuttling of lithium polysulfides. The Li–S cell with BTT delivers a specific discharge capacity of 1,239 mAh g−1 (based on sulfur), and high cycling stability of over 300 cycles at 1C rate. A Li–S pouch cell with BTT is also evaluated to prove the concept. This study constructs an ingenious interface reaction based on bond chemistry, aiming to solve the inherent problems of Li–S batteries.

scholarly journals Fabrication of a liquid cell for in situ transmission electron microscopy

Microscopy ◽  
2020 ◽  
Author(s):  
Xiaoguang Li ◽  
Kazutaka Mitsuishi ◽  
Masaki Takeguchi
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cost Effective ◽  
Production Method ◽  
Microscopy Imaging ◽  
Transmission Electron ◽  
In Situ Electron Microscopy ◽  
Liquid Cell ◽  
Si Wafer

Abstract Liquid cell transmission electron microscopy (LCTEM) enables imaging of dynamic processes in liquid with high spatial and temporal resolution. The widely used liquid cell (LC) consists of two stacking microchips with a thin wet sample sandwiched between them. The vertically overlapped electron-transparent membrane windows on the microchips provide passage for the electron beam. However, microchips with imprecise dimensions usually cause poor alignment of the windows and difficulty in acquiring high-quality images. In this study, we developed a new and efficient microchip fabrication process for LCTEM with a large viewing area (180 µm × 40 µm) and evaluated the resultant LC. The new positioning reference marks on the surface of the Si wafer dramatically improve the precision of dicing the wafer, making it possible to accurately align the windows on two stacking microchips. The precise alignment led to a liquid thickness of 125.6 nm close to the edge of the viewing area. The performance of our LC was demonstrated by in situ transmission electron microscopy imaging of the dynamic motions of 2-nm Pt particles. This versatile and cost-effective microchip production method can be used to fabricate other types of microchips for in situ electron microscopy.

scholarly journals Dendrite-Free and Stable Lithium Metal Battery Achieved by a Model of Stepwise Lithium Deposition and Stripping

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Tiancun Liu ◽  
Jinlong Wang ◽  
Yi Xu ◽  
Yifan Zhang ◽  
Yong Wang
Keyword(s):  
Reduction Method ◽  
Coulombic Efficiency ◽  
List Type ◽  
Lithium Metal ◽  
Metal Anode ◽  
In Situ Raman ◽  
Unique Model ◽  
Li Metal Anode ◽  
Pyridinic N

Highlights A facile method is adopted to obtain cucumber-like lithiophilic composite skeleton. Massive lithiophilic sites in cucumber-like lithiophilic composite skeleton can promote and guide uniform Li depositions. A unique model of stepwise Li deposition and stripping is determined. Abstract The uncontrolled formation of lithium (Li) dendrites and the unnecessary consumption of electrolyte during the Li plating/stripping process have been major obstacles in developing safe and stable Li metal batteries. Herein, we report a cucumber-like lithiophilic composite skeleton (CLCS) fabricated through a facile oxidation-immersion-reduction method. The stepwise Li deposition and stripping, determined using in situ Raman spectra during the galvanostatic Li charging/discharging process, promote the formation of a dendrite-free Li metal anode. Furthermore, numerous pyridinic N, pyrrolic N, and CuxN sites with excellent lithiophilicity work synergistically to distribute Li ions and suppress the formation of Li dendrites. Owing to these advantages, cells based on CLCS exhibit a high Coulombic efficiency of 97.3% for 700 cycles and an improved lifespan of 2000 h for symmetric cells. The full cells assembled with LiFePO4 (LFP), SeS2 cathodes and CLCS@Li anodes demonstrate high capacities of 110.1 mAh g−1 after 600 cycles at 0.2 A g−1 in CLCS@Li|LFP and 491.8 mAh g−1 after 500 cycles at 1 A g−1 in CLCS@Li|SeS2. The unique design of CLCS may accelerate the application of Li metal anodes in commercial Li metal batteries.

scholarly journals Improving Cyclability of Lithium Metal Anode via Constructing Atomic Interlamellar Ion Channel for Lithium Sulfur Battery

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Mao Yang ◽  
Nan Jue ◽  
Yuanfu Chen ◽  
Yong Wang
Keyword(s):  
Ion Channel ◽  
Coulombic Efficiency ◽  
Specific Capacity ◽  
Absorption Capacity ◽  
Lithium Metal ◽  
Metal Anode ◽  
Lithium Metal Anode ◽  
Li Ion ◽  
Sulfur Battery ◽  
Rapid Transfer

AbstractUniform migration of lithium (Li) ions between the separator and the lithium anode is critical for achieving good quality Li deposition, which is of much significance for lithium metal battery operation, especially for Li–sulfur (Li–S) batteries. Commercial separators such as polypropylene or polyethylene can be prepared by wet or dry processes, but they can indeed cause plentiful porosities, resulting in the uneven Li ion stripping/plating and finally the formation of Li dendrites. Thence, we constructed an atomic interlamellar ion channel by introducing the layered montmorillonite on the surface of the separator to guide Li ion flux and achieved stable Li deposition. The atomic interlamellar ion channel with a spacing of 1.4 nm showed strong absorption capacity for electrolytes and reserved capacity for Li ions, thus promoting rapid transfer of Li ions and resulting in even Li ion deposition at the anode. When assembled with the proposed separator, the Coulombic efficiency of Li||Cu batteries was 98.2% after 200 cycles and stable plating/stripping even after 800 h was achieved for the Li||Li symmetric batteries. Importantly, the proposed separator allows 140% specific capacity increase after 190 cycles as employing the Li–S batteries.

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