Binder chemistry sets the interfacial balance constant in CsPbBr3 nanocrystal supercapacitor electrodes
Abstract
Previous work on lead-free tin halide perovskites showed that the binder instead sets the electrolyte concentration at which capacitance is maximised, following the relationship 100 × [Li+]opt + PVDFwt% = ξInt with ξInt = 25 ± 2.5, established by varying the loading of a single polymer. Whether ξInt is universal or specific to that polymer has not been tested. Here, four binders spanning fluorinated (PVDF), carboxylic (PAA), cellulosic (CMC) and sulfonic (PEDOT:PSS) chemistry are compared on CsPbBr3 nanocrystal electrodes at four LiTFSI concentrations in acetonitrile, with binder loading fixed at 15 wt% and all other formulation variables held constant. The relationship applies to CsPbBr3: PVDF at 15 wt% gives an optimum at 0.10--0.15 M and 112 F g−1, against 126 F g−1 reported for CsSnCl3 under the same conditions, extending the result to a different B-site cation, halide and crystal system. PVDF and CMC optimise at 0.10 M, giving ξInt = 25, while PAA and PEDOT:PSS optimise at 0.15 M, giving ξInt = 30, with maximum values of 188 F g−1 for PAA and 146 mF cm−2 for PEDOT:PSS. The two binders showing the shift carry ionisable acid groups at high density, indicating that ξInt expressed in weight percent requires a binder-specific value. In all four electrodes, CsPbBr3 converts to PbBr2 and CsBr during electrochemical characterisation, and the surface lead content of the PEDOT:PSS electrode decreases.
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BibTeX
@misc{kumar2026binder,
title = {{Binder chemistry sets the interfacial balance constant in CsPbBr$_3$ nanocrystal supercapacitor electrodes}},
author = {Arun Kumar and Monojit Bag},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.14588},
eprint = {2609.14588},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.14588},
}
RIS
TY - UNPB
TI - Binder chemistry sets the interfacial balance constant in CsPbBr_3 nanocrystal supercapacitor electrodes
AU - Arun Kumar
AU - Monojit Bag
PY - 2026
DA - 2026/09/13
PB - arXiv
DO - 10.48550/arxiv.2609.14588
UR - https://arxiv.org/abs/2609.14588
AB - Previous work on lead-free tin halide perovskites showed that the binder instead sets the electrolyte concentration at which capacitance is maximised, following the relationship 100 × [Li^+]_opt + PVDF_wt% = ξ_Int with ξ_Int = 25 ± 2.5, established by varying the loading of a single polymer. Whether ξ_Int is universal or specific to that polymer has not been tested. Here, four binders spanning fluorinated (PVDF), carboxylic (PAA), cellulosic (CMC) and sulfonic (PEDOT:PSS) chemistry are compared on CsPbBr_3 nanocrystal electrodes at four LiTFSI concentrations in acetonitrile, with binder loading fixed at 15 wt% and all other formulation variables held constant. The relationship applies to CsPbBr_3: PVDF at 15 wt% gives an optimum at 0.10--0.15 M and 112 F g^−1, against 126 F g^−1 reported for CsSnCl_3 under the same conditions, extending the result to a different B-site cation, halide and crystal system. PVDF and CMC optimise at 0.10 M, giving ξ_Int = 25, while PAA and PEDOT:PSS optimise at 0.15 M, giving ξ_Int = 30, with maximum values of 188 F g^−1 for PAA and 146 mF cm^−2 for PEDOT:PSS. The two binders showing the shift carry ionisable acid groups at high density, indicating that ξ_Int expressed in weight percent requires a binder-specific value. In all four electrodes, CsPbBr_3 converts to PbBr_2 and CsBr during electrochemical characterisation, and the surface lead content of the PEDOT:PSS electrode decreases.
ER -