Effect of comb polymer dispersants with different molecular structures on the performance of LiFePO4 suspensions

• Published in: Journal of dispersion science and technology Vol. 45; no. 6; pp. 1241 - 1250
• Main Authors: Dong, Yarui, Xu, Jian, Du, Ping, Feng, Zhongjun, Zheng, Baicun
• Format: Journal Article
• Language: English
• Published: Philadelphia Taylor & Francis 2024; Taylor & Francis Ltd
• Subjects: Adsorption; Carboxyl group; Comb polymer dispersants; Density; Dispersants; LiFePO; Lithium; lithium ion batteries; Methacrylic acid; Molecular structure; Polyethylene glycol; Polymers; Rheological properties; rheology; Stability; Steric hindrance; Synergistic effect
• ISSN: 0193-2691; 1532-2351
• DOI: 10.1080/01932691.2023.2204152

A series of comb polymers poly(2-(dimethylamino)ethyl methacrylate (DMAEMA)-co-methacrylic acid (MAA)-co-methoxy polyethylene glycol methacrylate (MPEGMA)) (poly(DMAEMA-MAA-MPEGMA, DMM) were synthesized and used as N-methyl-2-pyrolidinone (NMP)-based lithium iron phosphate (LFP) suspension dispersants. The effects of the grafting density of the carboxyl group as the anchoring group and the chain length of the side chain of PEG, which plays the role of spatial site resistance, on the rheological properties and suspension stability of the slurry were systematically investigated. By investigating the adsorption amount and thickness of DMM on the LFP surface, combined with calculations based on the scalar law and Flory theory, the molecular structure of the comb polymer dispersant was revealed to influence the adsorption and dispersion performance. The dispersion of LiFePO 4 was due to the synergistic effects of adsorption and steric hindrance effect, which resulted that dispersants with medium carboxyl density and PEG side chain length can improve the dispersion performance and stability.