Bio-Derivative Galactomannan Gum Binders for Li₄Ti₅O₁₂Negative Electrodes in Lithium-Ion Batteries

Abstract

Two types of galactomannan gum derived from plant seeds, guar gum (GG) and tara gum (TG), were used for the first time as the binders for Li 4 Ti 5 O 12 (LTO) negative electrodes in lithium-ion batteries; they were thoroughly compared to typical carboxymethyl cellulose (CMC) binder using various characterization techniques. The galactomannan gums, branched polysaccharides, better facilitate the transport of lithium ions in LTO electrodes than CMC binder, a cellulose (linear polysaccharide) derivative, even though their binding capability is not as strong as CMC. This is attributed to a large extent of electrolyte uptake and a large LTO surface exposed to electrolyte when the gum binders are used. In particular, the GG-containing LTO electrode exhibits a high reversible capacity of 160.0 mAh g −1 at the 100 th cycle with 1 C current rate, whereas the CMC-containing LTO electrode has a reversible capacity of 150.1 mAh g −1 . The difference in capacity between the GG and CMC electrodes increased at higher current rates and was approximately 25 mAh g −1 at 10 C current rate. Nowadays, lithium-ion battery (LIB) has expanded its territory to electric vehicles (EV) and energy storage systems (ESS) from small mobile devices. The medium-or large-sized LIBs for EV and ESS require extraordinary long-cycled, high-powered, and high-capacity active materials. In this perspective, spinel-structured lithium titanium oxide (Li 4 Ti 5 O 12 , LTO) is an appropriate candidate for the anode material of LIBs used in EV and ESS because of its extremely stable structure and rapid lithium-ion transport during charge and discharge processes.1-3 Although the successful commercial application of LTO in LIB anodes has been recently achieved, minimal attention has been given to the polymeric binder that is an inactive but indispensable component of the LTO electrodes. The polymeric binder provides adhesion between active materials including conducting agents and current collector to form an electrically conductive integrated electrode.Two types of polymeric binders have been commercially used for LIBs: solvent-soluble polyvinylidene fluoride (PVdF) and watersoluble carboxymethyl cellulose (CMC) combined with waterdispersed styrene butadiene rubber (SBR). Unlike PVdF, CMC polymer is soluble in water, thus allowing the LIB manufacturing process to be environmentally friendly and inexpensive for recovering an organic solvent. These are the main reasons why most of the commercial negative electrodes are prepared from CMC binder combined with SBR. For LTO electrodes including TiO 2 , CMC polymer reported to have better binder performance from an electrochemical perspective of LTO electrodes than PVdF. [4][5][6] This was attributed to its low charge-transfer resistance, low activation energy for lithium-ion diffusion, and suitable electrolyte wettability of CMC-containing LTO electrodes. Recently, our group thoroughly investigated the effect of the degree of the substitution (DS) and molecular weight (MW) of CMC binder on the electrochemical perfo...

High Temperature Stable Separator for Lithium Batteries Based on SiO2 and Hydroxypropyl Guar Gum

“…This is due to the good affinity of the SiO 2 particles to organic-based electrolyte (1 M LiPF 6 in EC:DMC = 1:1 w / w ) [10]. The combination of excellent wettability, due to the hydrophilic characteristic of SiO 2 particles [7,8,9,25] and the chemical structure of guar gum [16], and relatively high internal porosity resulted in the high absorbed volume of electrolyte in the separator (after 30 and 60 min the weight of the membrane increased by 290% and 370%, respectively).…”

“…Additionally, Figure 7b shows the typical flat potential profile of Li + (de)insertion of in the LTO spinel structure, associated with the specific discharge capacity of 161 mAh·g −1 (at 0.1C). The first cycle potential profiles indicate as the LTO composite electrode [16] performed very well with the SiO 2 –HPG separator. With both electrodes no anomalous reactions or decompositions of the separator were observed.…”

“…Guar gums have been proved viable for electrochemical energy storage applications, such as binders for lithium titanium oxide (Li 4 Ti 5 O 12 or LTO) [16] and silicon [17,18,19] anodes in lithium-ion batteries and gel polymer electrolytes in super capacitors [20]. The advantages of using HPG compared with native guar gum are the enhanced water solubility and thermal stability [21].…”

“…The membranes were characterized with respect to porosity, electrolyte wettability, electrochemical and thermal stabilities, and, finally, tested as separator in half-cells (Li metal negative electrode) with lithium nickel-manganese-cobalt oxide (LiNi 1/3 Mn 1/3 Co 1/3 O 2 or NMC) and lithium titanate oxide (Li 4 Ti 5 O 12 or LTO) based positive electrodes, since those two materials are already used in commercial lithium-ion batteries [3,16]. …”

Water‐Soluble Green Binder for Li4Ti5O12 Anodes: Effect of Binder Choice on Lithium Storage

“…LTO anode with CMC binder shows excellent electrochemical performance over the conventional PVdF binder due to the improved electrode kinetics, lower charge transfer resistance, lower apparent activation energy and lower apparent diffusion activation energy. [6,7,[11][12][13][14][15] Towards this direction, we introduced a new acrylic family aqueous binder, viz., LA132 (À[ÀR 1 ÀR 2 ÀCH 2 ÀCH(CN)] n À ) with low charge transfer resistance and moderate adhesive property (due to the strong polar ÀCN group in the main chain segment of its structure) for LTO anode. It is quite interesting to note that the scarcely found reports dealing with the deployment of LA132 binder in literature describe the effect of LA132 towards the electrochemical performance of LTO electrode with respect to supercapacitors; whereas no single report that deals with the effect of LA132 binder to improve the electrochemical perform-ance of LTO in LIBs is found.…”