1. Negative electrode
As a binder: sodium carboxymethyl cellulose (CMC-Na) can firmly bond the negative electrode active material (such as graphite, silicon, etc.) and the conductive agent to the current collector, enhance the bonding force between the material particles, and prevent the active material from falling off during the charge and discharge cycle, thereby improving the cycle stability and service life of the battery. For example, in the graphite negative electrode of a lithium-ion battery, CMC-Na can make the graphite particles tightly bonded together to maintain the integrity of the electrode structure.
Improving electrode performance: It helps to form a stable and uniform electrode structure, improve the processing performance of electrode materials, enhance the integrity of the electrode, and further improve the performance and safety of the battery. In addition, CMC-Na can also improve the dispersion stability and fluidity of water-insoluble substances in the battery electrolyte, which helps to improve the energy density and charge and discharge efficiency of the battery.
2. Silicon-based negative electrode
Enhance the bonding effect: For high-capacity silicon negative electrode materials, the carboxyl functional groups in sodium carboxymethyl cellulose (CMC-Na) can form hydrogen bonds or covalent bonds with silicon dioxide (SiO₂) and silanol (-Si-OH) groups on the silicon surface, enhance the bonding between silicon particles and between silicon particles and current collectors, effectively inhibit the volume expansion of silicon during charging and discharging, and improve the cycle performance of silicon-based negative electrodes.
3. Hard carbon negative electrode
Fix particles and conduct electrons: In sodium batteries, sodium carboxymethyl cellulose (CMC-Na) is used as a binder for hard carbon negative electrode materials. It can firmly bond hard carbon particles together to form a solid negative electrode structure. It also has good electronic conductivity, which can promote the migration of electrons in negative electrode materials and improve the conductivity and overall performance of the battery.
