The Modification of Carboxymethyl Cellulose with Lithium Acrylate as Anode Binder for Improving Performance of Lithium Ions Battery at Subzero Temperatures

Abstract

This study demonstrates the modification of carboxymethyl cellulose (CMC) with lithium acrylate as anode binder to enhance lithium ions battery (LIBs) performance for energy storage at subzero temperatures. CMC is modified with lithium acrylate (LA) via Oxa-Michael reaction to obtain the product, denoted as CMC-LA. Subsequently, LIBs are constructed by graphite-based anode with CMC-LA and CMC binders, respectively denoted as LIB-CMC-LA and LIB-CMC for coin cells with lithium metal. The data for capacities (C), resistances for charge transfer (Rct), and diffusion coefficients ([[EQUATION]]Li+) are respectively calculated from galvanic charge-discharge cycles, electrochemical impedance spectroscopy, and cyclic voltammetry from 25 to -13oC. At 25 oC, the data for C, Rct, and [[EQUATION]]Li+ of LIBS-CMC-LA and LIBs-CMC are respectively calculated as 365mAh/g, 15.9 Ω, and 9.84×10-10 cm2/s, as well as, 323mAh/g, 17.3Ω, and 2.7×10-10 cm2/s. At -5oC, the results of C, Rct, and [[EQUATION]]Li+ are the much better on LIB-CMC-LA (243mAh/g, 313 Ω, and 2.22×10-10 cm2/s) than LIBs-CMC (163mAh/g, 750 Ω, and 6.39×10-12 cm2/s). Noticeably, at -10 oC, the data for C, Rct, and [[EQUATION]]Li+ of LIBS-CMC-LA (163mAh/g, 613Ω, and 3.46×10-11) significantly diverge from those of LIBS-CMC (76mAh/g, 4000Ω, and 7.9×10-13), being coincided with the less exothermic area of CMC-LA than CMC in differential scanning calorimetry from 0 to -20oC. The study paves the way that the modification of CMC with lithium acrylate as an anode binder is a good method to improve the performance of LIBs at low temperature.

Keywords: Lithium ions battery, Subzero temperatures, Anode binder, Carboxymethyl cellulose, Lithium acrylate