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Abstract The interrelation is explored between external pressure (0.1, 1, and 10 MPa), solid electrolyte interphase (SEI) structure/morphology, and lithium metal plating/stripping behavior. To simulate anode‐free lithium metal batteries (AF‐LMBs) analysis is performed on “empty” Cu current collectors in standard carbonate electrolyte. Lower pressure promotes organic‐rich SEI and macroscopically heterogeneous, filament‐like Li electrodeposits interspersed with pores. Higher pressure promotes inorganic F‐rich SEI with more uniform and denser Li film. A “seeding layer” of lithiated pristine graphene (pG@Cu) favors an anion‐derived F‐rich SEI and promotes uniform metal electrodeposition, enabling extended electrochemical stability at a lower pressure. State‐of‐the‐art electrochemical performance is achieved at 1MPa: pG‐enabled half‐cell is stable after 300 h (50 cycles) at 1 mA cm−2rate −3 mAh cm−2capacity (17.5 µm plated/stripped), with cycling Coulombic efficiency (CE) of 99.8%. AF‐LMB cells with high mass loading NMC622 cathode (21 mg cm−2) undergo 200 cycles with a CE of 99.4% at C/5‐charge and C/2‐discharge (1C = 178 mAh g−1). Density functional theory (DFT) highlights the differences in the adsorption energy of solvated‐Li+onto various crystal planes of Cu (100), (110), and (111), versus lithiated/delithiated (0001) graphene, giving insight regarding the role of support surface energetics in promoting SEI heterogeneity.
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Enabling Uniform and Accurate Control of Cycling Pressure for All‐Solid‐State Batteries
Abstract All‐solid‐state batteries are emerging as potential successors in energy storage technologies due to their increased safety, stemming from replacing organic liquid electrolytes in conventional Li‐ion batteries with less flammable solid‐state electrolytes. However, all‐solid‐state batteries require precise control over cycling pressure to maintain effective interfacial contacts between materials. Traditional uniaxial cell holders, often used in battery research, face challenges in accommodating electrode volume changes, providing uniform pressure distribution, and maintaining consistent pressure over time. This study introduces isostatic pouch cell holders utilizing air as pressurizing media to achieve uniform and accurately regulated cycling pressure. LiNi0.8Co0.1Mn0.1O2| Li6PS5Cl | Si pouch cells are fabricated and tested under 1 to 5 MPa pressures, revealing improved electrochemical performance with higher cycling pressures, with 2 MPa as the minimum for optimal operation. A bilayer pouch cell with a theoretical capacity of 100 mAh, cycled with an isostatic pouch cell holder, demonstrated a first‐cycle Coulombic efficiency of 76.9% and a discharge capacity of 173.6 mAh g−1(88.1 mAh), maintaining 83.6% capacity after 100 cycles. These findings underscore the effectiveness of isostatic pouch cell holders in enhancing the performance and practical application of all‐solid‐state batteries.
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- Award ID(s):
- 2011967
- PAR ID:
- 10532161
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Energy Materials
- Volume:
- 14
- Issue:
- 30
- ISSN:
- 1614-6832
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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