Gelatin and Alginate Binders for Simplified Battery Recycling

Abstract

The water-soluble biopolymers, gelatin and sodium alginate, were investigated as potential alternative binders for use in lithium-ion battery anodes. The polymers were modified using a deep eutectic solvent (DES) made from choline chloride and glycerol. It was found that the addition of the DES resulted in greater plasticity and adhesion with respect to the unmodified binders and also to the current commonly used PVDF or CMC/SBR binders. Both the modified gelatin and sodium alginate binders are dispersible in water and can be rapidly delaminated by using mild ultrasound. These latter points are key steps in the function of the anode material and the subsequent recycling at the end of life. Imaging of the coatings formed using scanning electron microscopy and atomic force microscopy showed that the two types of binders dispersed themselves differently around the graphite particles, with the gelatin binder being distributed across the entire electrode surface, whereas the sodium alginate binder remained located at the hydrophilic edge planes of the graphite.

Improving the Conductivity of Graphite-Based Lithium-Ion Battery Anodes Using Polyaniline–Alginate Blends

“…Atomic force microscopy (AFM) was measured using a Bruker Dimension Icon AFM, with a Nanoscope V controller and Nanoscope 9.4 imaging software. AFM was carried out using the Peak Force Tapping (PFT) imaging mode, similar to previous studies. , A RTSEP-300 probe with a spring constant of 40 N m –1 was used to acquire the height images and data used by the Nanoscope 16.4 software to calculate the Sneddon modulus, giving a modulus scan of the surface. Scratch testing was carried out using a ST200 scratch tester with a diamond probe.…”

“…However, there is an interesting change between the AFM modulus images shown in Figure 5 and those found in a previous study investigating modified water miscible anode binders, including NaAlg. 11 Those AFM images did not show resolved carbon black (CB) particles in the NaAlg polymeric regions, indicating weaker interactions between the NaAlg and the CB due to the purely hydrophilic nature of the polymer. On the other hand, the gelatin samples, which were amphiphilic, showed resolved CB particles as the presence of both hydrophilic and hydrophobic groups allowed the polymer to interact with and "wet" the CB.…”

“…However, there is an interesting change between the AFM modulus images shown in Figure and those found in a previous study investigating modified water miscible anode binders, including NaAlg . Those AFM images did not show resolved carbon black (CB) particles in the NaAlg polymeric regions, indicating weaker interactions between the NaAlg and the CB due to the purely hydrophilic nature of the polymer.…”

Direct re-lithiation strategy for spent lithium iron phosphate battery in Li-based eutectic using organic reducing agents

“…The temperature that operated in the program was from 25 to 550 °C with 5 °C min −1 of a heating rate and 20 mL min −1 of a nitrogen flow. Reference materials were prepared for TGA-DSC by forming a slurry of the commercial LiFePO 4 with carbon black and different known binders at a weight ratio of 90 : 5 : 5, using a method adapted from Scott et al 31 The PVDF sample was prepared using NMP as a solvent, whereas the CMC-SBR (1 : 1 weight ratio) sample was prepared using water. The homogeneous slurry was coated onto aluminium foil.…”

Sustainable stretchable batteries for next-generation wearables

“…and protein-based (gelatin and caseinate) materials have been proposed to replace nonbiodegradable and petrochemical-derived uorinated and styrene rubber polymers. [143][144][145] However, to embed stretchability and soness, a higher volume fraction of the elastomer is typically needed to maintain the mechanical properties of the composite. 146 Here, the challenge remains of balancing high active material loading without affecting the mechanical properties of the active electrode.…”