Polyamidoamine dendrimer-based binders for high-loading lithium–sulfur battery cathodes. (January 2016)

• Record Type: Journal Article
• Authors: Bhattacharya, Priyanka; Nandasiri, Manjula I.; Lv, Dongping; Schwarz, Ashleigh M.; Darsell, Jens T.; Henderson, Wesley A.; Tomalia, Donald A.; Liu, Jun; Zhang, Ji-Guang; Xiao, Jie
• Is Part Of: Nano energy. Volume 19(2016:Jan.)
• Page Start: 176
• Page End: 186
• Publication Date: 2016-01
• Subjects: PAMAM dendrimers -- Lithium–sulfur batteries -- Binder -- Energy storage -- High sulfur loading; Nanoscience -- Periodicals; Nanotechnology -- Periodicals; Nanostructured materials -- Periodicals; Power resources -- Technological innovations -- Periodicals; Nanoscience; Nanostructured materials; Nanotechnology; Power resources -- Technological innovations; Periodicals; 621.042
• DOI: 10.1016/j.nanoen.2015.11.012
• Languages: English
• ISSNs: 2211-2855

Abstract

Abstract: Lithium–sulfur (Li–S) batteries are regarded as one of the most promising candidates for next generation energy storage. To realize their practical application, however, a high S active material loading is essential. The binder material used for the cathode is therefore crucial as this is a key determinant of the bonding interactions between the active material (S) and electronic conducting support (C), as well as the maintenance of intimate contact between the electrode materials and current collector. Here, we investigated the application of polyamidoamine (PAMAM) dendrimers as functional binders in Li–S batteries. Utilizing the high degree of surface functionalities, interior porosities, and polarity of the PAMAM dendrimers, it is demonstrated that high S loadings (>4 mg cm −2 ) can be easily achieved using simple processing methods. An exceptional electrochemical cycling performance was obtained as compared to cathodes with conventional linear polymeric binders such as carboxymethyl cellulose (CMC) and styrene–butadiene rubber (SBR), which was attributed to better interfacial interactions between the dendrimers and the C/S composite materials, as well as better electrolyte wetting due to the dendrimer spherical molecular, porous architectures. Furthermore, the dendrimer-based binders also physically and chemically trapped the polar polysulfides, thus demonstrating the significant utility of this new nanosized binder architecture. Graphical abstract: The critical nanoscale design parameters of dendrimers are exploited as functional water-soluble binders for high sulfur loading lithium–sulfur batteries. The high functional group density, high curvature and porosity, polarity, and ample nitrogen and oxygen functional groups in the dendrimers enabled strong dendrimer interactions with the carbon–sulfur composites, and superior cyclability compared to linear water-soluble binders such as CMC-SBR. Highlights: PAMAM dendrimer binders for high S-loading cathodes for Li-S batteries proposed. More than 100 cycles with 85–98% capacity retention obtained with dendrimer binders. Nanoscale, porous dendrimers physically and chemically trapped polysulfides. High density of surface functional groups provided strong interactions with C and S.