Characteristics of CMC from Corncob and its Application as Electrode Binder in Lithium Ion Battery

Abstract

Corncobs are a waste product from corn farming that are abundant in Indonesia. Corncobs have a high cellulose content, more than 40%, which made it useful for synthesizing CMC. CMC is a cellulose derivative that is widely used in many industries such as food, pharmaceutical, detergent, textile, cosmetic product and binder. In this paper, we use CMC that are synthesized from corncobs as binder in the electrodes of lithium ion battery. The steps of synthesizing CMC from corncobs started with the isolation of the cellulose, then followed by the processes of alkalization, carboxymethylation and finally the purification. FTIR spectrum shows that CMC are successfully synthesized. The presence of strong absorption band at 1613 cm-1 is related to the stretching vibration of the carboxyl group (COO-). The absorption in the 1300–1450 cm-1 region is due to symmetrical deformations of CH2 groups. While the broad absorption around 3427 cm-1 is due to the stretching of the hydroxyl groups (-OH). Test on three samples of different sizes, (mesh-100, mesh-60 and mesh-40) gives CMC purity values of 98.69%, 98.56% and 97.77%, respectively. In the application of CMC as anode binder, the best composition is 4% CMC, where it gives the highest conductivity of 0.587 S/cm. Voltammogram measurement with a scan rate of 50 mV/s in the voltage range of -1 to 1 Volt gives the capacitance value of 2237 μF.

Innovative and Economically Beneficial Use of Corn and Corn Products in Electrochemical Energy Storage Applications

“…110 Many innovative uses of corn, corn byproducts, and corn industrial products have been proposed as well. 121,30,29,28,122 In this section, several representative cases are reviewed. CMC has been considered as the precedent that opened the avenue for the investigation of water-soluble binders for highcapacity electrode materials.…”

“…It has been demonstrated that CMC binder can be fabricated based on corn stover through an eco-friendly and economical approach. 28,122,123 For example, Hidayat et al synthesized CMC binder for lithium-ion batteries using corn cob. 28 Corn starch has been extensively studied as the binder for silicon-based anodes due to its low cost and biodegradability.…”

“…28,122,123 For example, Hidayat et al synthesized CMC binder for lithium-ion batteries using corn cob. 28 Corn starch has been extensively studied as the binder for silicon-based anodes due to its low cost and biodegradability. 30,121 One example was provided by Rohan et al 29 As shown in Figure 11a,b, corn starch and maleic anhydride are dissolved in hot water, stirred for 1 h at room temperature, and then heated at 120 °C for 12 h for cross-linking.…”

“…The enhanced adhesion due to the chemical bonds between the binder and the silicon nanoparticles demonstrates a self-healing effect when locally broken . Many innovative uses of corn, corn byproducts, and corn industrial products have been proposed as well. ,,,, In this section, several representative cases are reviewed.…”

“…When a buffer solution with a pH value of 3 is used for the electrode fabrication, a grafting esterification reaction between the hydroxyl groups on the silicon surface and the carboxyl groups of CMC is greatly favored, and as a result, the electrode displays a remarkable cycle life. It has been demonstrated that CMC binder can be fabricated based on corn stover through an eco-friendly and economical approach. ,, For example, Hidayat et al synthesized CMC binder for lithium-ion batteries using corn cob …”