Date: 2025-04-22 hits: 112
A. Introduction
As an important energy storage technology, the improvement of performance and safety of lithium batteries has become a key focus of research and industrial development. Among the numerous components of lithium batteries, sodium carboxymethyl cellulose (CMC) plays an indispensable role.
B. Definition and function of CMC for lithium batteries
（1） Definition
CMC is a water-soluble polymer with a unique chemical structure, which contains carboxymethyl functional groups on its molecular chain, endowing it with good solubility and specific physicochemical properties in water.
（2） Function
1. Adhesive effect
In lithium batteries, CMC serves as a binder to tightly bond the active material and conductive agent, forming a stable electrode structure. This bonding effect ensures that the electrode can firmly adhere to the current collector during repeated charging and discharging processes, reducing the detachment and loss of the active material, thereby maintaining the capacity and cycle life of the battery.
2. Dispersion effect
The uniform distribution of negative electrode material in the slurry is crucial for battery performance. CMC can effectively prevent the agglomeration of negative electrode materials, allowing active material particles to be uniformly dispersed in the slurry, thereby improving the electrochemical performance of the electrode and ensuring the stability and consistency of the battery during charging and discharging processes.
3. Stabilizing effect
The stabilizing effect of CMC on electrode processing performance should not be underestimated. It can optimize the process parameters during electrode preparation, improve production efficiency and product quality. Meanwhile, by assisting in improving the cycling performance of the battery, CMC helps to extend the battery's lifespan and reduce its decay rate.
C. The application of CMC in lithium batteries
（1） As a bonding agent
The active material and conductive agent form an electrode with good mechanical strength and electrical properties under the bonding of CMC. This stable electrode structure can withstand the volume changes and stresses during battery charging and discharging, maintaining the stability of battery performance. For example, in the positive electrode of lithium-ion batteries, CMC works synergistically with other binders to ensure the stability and conductivity of the positive electrode material. In the negative electrode, CMC effectively bonds negative electrode materials such as graphite, preventing structural damage during cycling.
（2） As a dispersant
In the preparation process of battery slurry, CMC can evenly disperse the negative electrode material, avoiding situations where the local concentration is too high or too low. This helps to improve the utilization rate and charge discharge performance of electrodes, and reduce polarization phenomena inside the battery. Taking astatine based negative electrode materials as an example, due to their high specific capacity and large volume expansion, they are prone to agglomeration in the slurry. The addition of CMC can effectively disperse silicon particles, reduce agglomeration, and improve the cycling stability of the battery.
（3） As a stabilizer
The stabilizing effect of CMC on electrode processing performance is reflected in multiple aspects. It can adjust the rheological properties of the slurry, making it more suitable for coating processes. At the same time, during the charging and discharging process of the battery, CMC helps to maintain the structural integrity of the electrode, reduce the occurrence of side reactions, and thus improve the cycling performance of the battery.
D. Characteristics and advantages of CMC
（1） High purity
Battery grade CMC has the characteristics of high purity and low metal ion content. This means that during the operation of the battery, the side reactions caused by impurities and the degradation of battery performance are reduced, thereby improving the overall performance and safety of the battery.
（2） Good compatibility
The good compatibility with other battery materials such as SBR latex enables CMC to work synergistically in complex battery systems, jointly improving the overall performance of the battery.
（3） Thickening and anti settling
By increasing the viscosity of the slurry, CMC effectively prevents the settling of particles in the slurry, ensuring the uniformity and stability of the slurry. This is crucial for the coating process in electrode preparation, ensuring consistency in electrode thickness and composition.
（4） Improve peel strength
Enhancing the peel strength of the electrode means that the electrode is less prone to detachment and damage when subjected to mechanical stress, thereby improving the reliability and stability of the battery.
E. Production and market situation of CMC
（1） Production process
1. Water Media Law
The water-based method is a traditional production process that has the advantages of simple process and low cost, but the quality and performance of the product are relatively average, making it suitable for some application fields that do not require high performance.
2. Solvent method
The solvent method can produce CMC products with higher quality and performance, suitable for producing CMC for mid to high end lithium batteries. This method allows for more precise control of reaction conditions by using organic solvents as reaction media, resulting in higher purity and better performance CMC products.
（2） Market situation
In recent years, the global CMC market for lithium batteries has shown a significant growth trend. This is mainly attributed to the rapid expansion of the new energy vehicle market, the popularity of portable electronic devices, and the growing demand in the energy storage field. According to the latest market research report, it is expected that this growth trend will continue in the coming years, and the market size will further expand.
F. Latest developments in CMC
（1） Ultra pure CMC
The first batch of AkuPure delivered by Norion is an ultra pure CMC product specifically designed for lithium batteries. Its high purity and low insoluble content not only improve the production efficiency of batteries but also significantly enhance their performance. This innovative product provides lithium battery manufacturers with a better choice, helping to further improve the energy density, cycle life, and safety of lithium batteries.
（2） High performance CMC
Shuoyingfeng has completed a Series B financing of tens of millions of yuan, with its main products being high-performance CMC series, including battery grade CMC Li/CMC Na, ultra-high viscosity CMC, and ultra-low viscosity CMC. These products have the advantages of wide viscosity range, high stability, low gel insoluble, and can meet the diversified needs of different types of lithium batteries. For example, ultra-high viscosity CMC is suitable for battery systems that require extremely high bonding strength, while ultra-low viscosity CMC is suitable for application scenarios that require rapid dispersion and penetration.
G. Conclusion
In summary, lithium battery CMC plays a crucial role in battery manufacturing. Its functions as a binder, dispersant, and stabilizer, as well as its high purity, good compatibility, thickening, anti settling, and improved peel strength advantages, effectively ensure the performance and stability of lithium batteries.
