Regulation of SEI Formation by Anion Receptors to Achieve Ultra‐Stable Lithium‐Metal Batteries

Abstract

Despite high specific capacity (3860 mAh g−1), the utilization of Li‐metal anodes in rechargeable batteries are still hampered due to their insufficient cyclability. Herein, we report an anion‐receptor‐mediated carbonate electrolyte with improved performance and can ameliorate the solid electrolyte interphase (SEI) composition comparing to the blank electrolyte. It demonstrates a high average Coulombic efficiency (97.94 %) over 500 cycles in the Li/Cu cell at a capacity of 1 mAh cm−2. Raman spectrum and molecular modelling further clarify the screening effects of the anion receptor on the Li+‐PF6− ion coupling that results in the enhanced ion dynamics. The X‐ray photoelectron spectroscopy (XPS) distinguishes the disparities in the SEI components of the developed electrolyte and the blank one, which is rationalized by the molecular insights of the Li‐metal/electrolyte interface. Thus, we prepare a 2.5 Ah prototype pouch cell, exhibiting a high energy density (357 Wh kg−1) with 90.90 % capacity retention over 50 cycles.

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

“…[12] However,inactive Li still appears with the above state-of-the-art inhibitory methodologies and the inferior lifespan is not capable of being employed in practical applications. [13] Consequently,new methodologies to conquer the issues of inactive Li are strongly necessary.Recently,cryotransmission electron microscopy (cryo-TEM) has been introduced to visualize the structure and chemistry of sensitive electrode materials, [14] which enables the underlying recognition and future resolution of inactive Li. Thec omponents and complex nanostructures of inactive Li in at ypical ether electrolyte have been preliminarily revealed, indicating that inactive Li includes Li 2 O-massive SEI and Li debris wrapped by SEI.…”

Enhancing Cellulose‐Based Separator with Polyethyleneimine and Polyvinylidene Fluoride‐Hexafluoropropylene Interpenetrated 3D Network for Lithium Metal Batteries

“…In contrast, the PE separator has inherent hydrophobicity, low surface energy, and poor affinity for polar liquid electrolytes, which limit the performance and cycle life of the LMBs. [26] As shown in Figure 6f, it is obvious that with the gradual increase of current density, the discharge capacity decreases. At the same rate, the capacity of the battery fabricated with the PIC separator is superior to that of the PE separator.…”

Designing Boron‐Based Single‐Ion Gel Polymer Electrolytes for Lithium Batteries by Photopolymerization

“…These peaks disappeared in the following cycles. We believe this might be a contribution to the formation of the SEI although a deeper analysis (e.g., such as in situ micro-FTIR spectroscopy [33] or X-ray photoelectron spectroscopy [34] ), which is outside the scope of this work, would be needed to study this phenomenon further. Dur- ing the anodic scans (Li 0 /electrolyte/stainless-steel cells), no oxidation currents were observed up to 2.49 V versus Li 0 /Li + for the SIPE-FG-60G4 cell and 3.91 V versus Li 0 /Li + for the SIPE-FF-60G4 cell (Figure 5).…”