(Invited) Polymer Binder Materials with High Density Functional Groups for Lithium/Sodium Ion Secondary Batteries

Résumé fourni par la source

Hard carbons (HC) has been a promising anode materials for sodium ion secondary batteries (SIBs), however, it suffers limited ion diffusion kinetics, low initial coulombic efficiency (ICE), uncontrollable electrolyte decomposition, sluggish rate capability and so forth. Under these context, there are expectation toward suitable binder materials which can address to these problems. In the present work, we employ water soluble poly(hydroxycarbonylmethylene) (PFA) binder [1,2] derived from the corresponding ester for HC anode in SIBs. The high density functional groups on polymer binder provides improved ion diffusion, higher initial coulombic efficiency (ICE) of over 80%, and specific capacity of 288 mAhg-1 and 254 mAhg-1 at 30 mAg-1 and 60 mAhg-1, respectively, which are superior to HC electrodes based on PAA and PVDF binders. This binder modifies SEI and led to enhanced Na+ kinetics at the interface such as lower activation energy of 50.7 kJmol-1, Na+ ion diffusion coefficient of 4.64E-11 cm2s-1 and lower RSEI when compared with PAA/HC and PVDF/HC. The peeling force of the PFA binder-containing HC electrode was 12.5 N, which was higher than PAA (11.5 N) and PVDF (9.8 N) electrodes due to the dense amount of -COOH groups present in PFA. After charge-discharge cycles, no loss of electrode integrity within electrode was observed by SEM. We further designed high density poly(ionic liquid) (HDPIL) by neutralization of PFA with imidazolium hydroxide [3]. The obtained HDPIL was also found to be high performing anodic binder both for LIBs and SIBs. [1] A. Patra, N. Matsumi, Charge-discharge Behavior of Lithium-ion Batteries Using a Polymer Electrolyte Bearing High-Density Functional Groups, ACS Appl. Ener. Mater., 6 (2023) 11973. [2] A. Patra, N. Matsumi, Water-soluble Densely Functionalized Poly(hydroxycarbonylmethylene) Binder for Higher-performance Hard Carbon Anode-based Sodium-ion Batteries, J. Mater. Chem. A., 12 (2024) 11857. [3] A. Patra, N. Matsumi, Densely Imidazolium Functionalized Water Soluble Poly(ionic liquid) Binder for Enhanced Performance of Carbon Anode in Lithium/Sodium-Ion Batteries, Advanced Energy Materials (2024) 2403071.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.