In this study, we present a novel polymeric binder system for Si anodes consisting of PAA, a chemical switch (ammonia, NH 3), and a crosslinker (branched polyethylenimine, PEI). Although adhesive polymeric binders, such as poly(acrylic acid) (PAA), mitigate this issue, the cycling performance of the fabricated Si anodes is still far from meeting the criteria of practical applications. However, the drastic volumetric changes of Si upon lithiation/delithiation hinder the practical use of Si anodes. Silicon (Si) is a promising high-capacity anode material for high-energy-density lithium-ion batteries. This restorable neutralization process of PAA binders represents an innovative strategy of mitigating issues from slurry processing of Si particles to achieve concurrent improvements in high-quality lamination and cycling performance. Additionally, the half-cells using the PAA-50%NH 3 binder can deliver 60% capacity retention over 100 cycles at C/3 rate, affording a 23.8% increase compared to PAA-Li half-cells. The best-performing composition of 50% neutralization (PAA-50%NH 3) provides comparable rheological response as a PAA-Li binder as well as much improved cycling performance. more » Interestingly, the resulting ammonium carboxylate groups may cleave during the drying process to restore the neutralized PAA (PAA-NH 3) binders to their pristine states. A weak base, ammonia (NH 3), was discovered as a neutralizing agent that still promotes rheological response of binder solutions but results in a reduced pH increase. Herein, a novel neutralization process for PAA binders is developed. However, the significantly increased basicity causes degradation of Si particles while the irreversible conversion of carboxylic acid groups to lithium carboxylates undermines the binding strength, collectively leading to adverse cycling performance of the fabricated Si anodes. Neutralization of poly(acrylic acid) (PAA)-based binders using lithium hydroxide is a common strategy for fabricating silicon anode laminates, which improves rheological properties of slurries toward high-quality electrode laminates. Energy Frontier Research Center (EFRC) Center for Electrical Energy Storage (CEES) Sponsoring Org.: USDOE Office of Science (SC), Basic Energy Sciences (BES) OSTI Identifier: 1469920 Alternate Identifier(s): OSTI ID: 1378805 Grant/Contract Number: AC02-06CH11357 Resource Type: Accepted Manuscript Journal Name: Advanced Energy Materials Additional Journal Information: Journal Volume: 7 Journal Issue: 17 Related Information: CEES partners with Argonne National Laboratory (lead) University of Illinois, Urbana-Champaign Northwest University Journal ID: ISSN 1614-6832 Publisher: Wiley Country of Publication: United States Language: English Subject: 25 ENERGY STORAGE ionic bonding Li‐ion batteries restoration of electrical interfaces Si composite = , Publication Date: Fri May 12 00:00: Research Org.: Argonne National Laboratory (ANL), Argonne, IL (United States). of Illinois at Urbana-Champaign, IL (United States). for Advanced Science and Technology Univ.
0 kommentar(er)
