Locust bean gum as green and water-soluble binder for LiFePO4 and Li4Ti5O12 electrodes

Abstract

Locust Bean Gum (LBG, carob bean gum) was investigated as an environmentally friendly, natural, and water-soluble binder for cathode (LFP) and anode (LTO) in lithium-ion batteries (Li-ion). For the first time, we show LBG as an electrode binder and compare to those of the most popular aqueous (CMC) and conventional (PVDF) binders. The electrodes were characterized using TGA/DSC, the galvanostatic charge–discharge cycle test, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). Thermal decomposition of LBG is seen to begin above 250 °C with a weight loss of about 60 wt% observed at 300 °C, which is sufficient to ensure stable performance of the electrode in a Li-ion battery. For CMC, weight loss at the same temperature is about 45%. Scanning electron microscopy (SEM) shows that the LFP–LBG system has a similar distribution of conductive carbon black particles to PVDF electrodes. The LTO–LBG electrode has a homogeneous dispersion of the electrode elements and maintains the electrical integrity of the network even after cycling, which leads to fast electron migration between LTO and carbon black particles, as well as ion conductivity between LTO active material and electrolyte, better than in systems with CMC and PVDF. The exchange current density, obtained from impedance spectroscopy fell within a broad range between 10−4 and 10−2 mA cm−2 for the LTO|Li and LFP|Li systems, respectively. The results presented in this paper indicate that LBG is a new promising material to serve as a binder. Graphic abstract

Xanthan gum as a water-based binder for P3-Na2/3Ni1/3Mn2/3O2

“…50 mAh g −1 using PVDF, both at 5 C (He et al, 2017). Similar results were observed with a locust bean gum binder in LiFePO 4 and Li 4 Ti 5 O 12 (Jakóbczyk et al, 2021). In all of these cases, the biopolymers/polysaccharides reduce both charge transfer resistance and polarization, which is beneficial for cycling at faster rates.…”

Prospects for managing end‐of‐life lithium‐ion batteries: Present and future

“…The development of binders that are soluble in nontoxic and readily available green reagents (such as water or ethanol) will replace the stubborn PVDF binders without compromising battery performance. [105][106][107][108] In this way, both the cost of manufacturing and recycling electrodes will be reduced, and the manufacturing and recycling steps will be simplified, with a consequent increase in safety. On the other hand, streamlining the production and assembly procedures would also facilitate automated disassembly.…”

White Latex: Appealing “Green” Alternative for PVdF in Electrode Manufacturing for Sustainable Li-Ion Batteries

“…Ascribed to the abundant carboxylic or hydroxyl groups, these binders, different from PVdF, intensively interact with the Si particles and thus efficiently buffer the volume changes of the material, which hence results in enhanced cycle performances. Polyacrylic acid and the polyacrylate modifier are also successfully employed with commercially available graphites. , Poly­(vinyl acetate) − and locust bean gum are also reported with different cathode materials as “green” succedanea of traditional PVdF; moreover, developing novel alternative binders other than the commonly used CMC has become a frontier topic with profound significance for clean and sustainable energy systems.…”

“…Polyacrylic acid and the polyacrylate modifier are also successfully employed with commercially available graphites. 40,41 Poly(vinyl acetate) 42−44 and locust bean gum 45 are also reported with different cathode materials as "green" succedanea of traditional PVdF; moreover, developing novel alternative binders other than the commonly used CMC has become a frontier topic with profound significance for clean and sustainable energy systems.…”