What is The Role of Carbon Black in Lithium Batteries?

 Under the development wave of new energy vehicles, the demand for lithium batteries continues to rise, which also brings unprecedented opportunities to the upstream raw material supply chain. However, with advancements in power battery technology, traditional materials are gradually unable to meet the requirements for reducing battery costs and improving energy density. Consequently, there is an accelerating adoption of new materials such as lithium-rich manganese, single crystal ternary, and silicon-based negative electrodes. Material and chemical system innovation is increasingly becoming a core competitive advantage for future enterprises within the battery industry chain. Conductive carbon black is a typical special carbon black widely utilized in conductive and anti-static products due to its excellent conductivity properties and cost-effectiveness. Currently, conductive carbon black is also gaining popularity in the energy field including applications in lithium-ion batteries, lead-acid batteries, and supercapacitors.

 

About Conductive Carbon Black

 

 

 

Conductive carbon black is a specialized form of carbon black that finds extensive usage in conductive and anti-static products due to its exceptional conductivity and cost-effectiveness. Carbon black-filled conductive polymer materials, encompassing functional polymers, novel coatings, as well as rubber and plastic products, have gained widespread applications across various industries such as mining pipes, cable shielding, aerospace industry, electronic appliances, petrochemicals, and transportation vehicles. Furthermore, conductive carbon black is highly favored in the energy sector for diverse applications including lithium-ion batteries (power), lead-acid batteries, and supercapacitors. The application properties of conductive carbon black are closely linked to its own conductivity which primarily relies on four factors: microcrystalline structure, surface structure, aggregate structure,and particle size distribution.

 

Development of Conductive Carbon Black

There are three primary categories of conductive carbon black products: by-product carbon black (derived from heavy oil gas as a secondary product), acetylene carbon black, and furnace conductive carbon black. Presently, renowned global manufacturers of carbon black such as Birla Carbon Black, Cabot, Black Cat Shares, Yongdong Shares, etc., offer their own versions of conductive carbon black products. Due to commercial interests, these companies strictly maintain the confidentiality of relevant technical information. Consequently, there exists a significant disparity in technical indicators among the products and even some products with similar technical indicators demonstrate varying application performance.

The performance of carbon black is determined by its fundamental properties and distribution level, including the size of primary particles, porosity, structure, and surface chemical properties. Currently, it is widely recognized that low specific surface area, high oil absorption value, and low metal ion content are crucial technical indicators for successful application of conductive carbon black. Furthermore, in terms of production and application processes, the distribution level of carbon black is significantly influenced by mixing equipment, formulation (including the choice of dispersant), and physical form which also impact electrical conductivity.

 

1. Particle Size of Carbon Black

In theory, the smaller the particle size of carbon black, the higher the particle density per unit volume, which is advantageous for enhancing electrical conductivity. This phenomenon is commonly observed in rubber products. However, when utilized in conductive plastic products, excessively small carbon black particles can result in poor dispersion due to insufficient shear force during plasticization. Consequently, carbon black aggregates into numerous tiny clusters within the matrix material, leading to diminished mechanical properties and a loss of practical value in conductive plastic products. Therefore, it becomes imperative to control the particle size of carbon black within a specific range to ensure optimal dispersion in plastics and significantly increase the number of carbon black particles per unit volume. This will enhance electrical conductivity without causing substantial damage or compromising mechanical properties.

 

2. Structure of Carbon Black

 

The DBP value reflects the structure of carbon black aggregates, with higher values indicating a chain-branched structure and good electrical conductivity. Carbon black derived from heavy oil gas production exhibits significantly high DBP values, suggesting an electron microscope observation of empty shells and a less developed microstructure. Its enhanced conductivity can be attributed to either its larger volume per unit mass or shear-induced destruction of the primary structure, resulting in the generation of numerous new particles. To achieve optimal electrical conductivity in plastics, it is preferable for carbon black to possess larger particle sizes and simpler structures that ideally form linear arrangements. This promotes dispersion within plastics while facilitating the formation of conductive networks with minimal amounts of carbon black.

 

3. Roughness of Carbon Black

Since the conductivity of carbon black requires some roughness to form conducting channels, the difference between the nitrogen adsorption surface area and the CTAB surface area of carbon black is required to be large.

 

4. Surface Volatiles of Carbon Black

The volatiles on the surface of carbon black mainly consist of organic groups and residual oil films that have not undergone complete cracking, leading to the formation of an insulating layer. This layer increases the barrier between carbon black particles, which significantly affects conductivity. Therefore, it is essential to control these volatiles within a lower range.

 

5. Ash and Moisture

The high levels of ash and moisture in carbon black not only result in a reduction of its quantity, but also have a detrimental impact on its electrical conductivity. Therefore, it is crucial to exercise caution in controlling the ash and moisture content during the production process.

 

Carbon Black Grinding Mill

According to the aforementioned properties, a smaller particle size of conductive carbon black is beneficial for enhancing its conductivity. However, it is also important to ensure that the particle size falls within an appropriate range. Clirik's HGM ultrafine mill is well-suited for meeting the production requirements of conductive carbon black. Typically, the ultrafine mill production line comprises a hammer crusher, bucket elevator, storage bin, vibration feeder, micro-grinding host, frequency conversion classifier, double cyclone collector, pulse dust removal system, high-pressure fan, air compressor, electrical control system and other components. The bulk material is initially crushed by the hammer crusher into feed particles (approximately 1cm) suitable for processing in the ultrafine mill. By adjusting the speed of the mill analysis machine accordingly, desired fineness can be achieved to meet specific production requirements. Manual packaging into bags or utilization of an automatic micro-powder baler can be employed as per preference while selecting different types of grinding machines based on specific needs.

 

 

HGM Ultrafine Grinding Mill

Capacity: 0.2-45 t/h

Feed Size: ≤20 mm

Powder Fineness: 325-3000 mesh

 

Mill Advantages

(1) Efficient and Energy-Efficient

 The output is more than double that of an air mill, a stirring mill, and a ball mill when the fineness of the finished product and motor power are kept constant.

 

(2) The parts have a long service life

The grinding roller and grinding ring are forged using special materials, which greatly enhance their utilization efficiency. Generally, they can be utilized for more than a year while processing calcium carbonate and calcite, with a lifespan ranging from 2 to 5 years.

 

(3) High safety and reliability

The absence of rolling bearings or screws in the grinding chamber eliminates concerns regarding vulnerable bearings and their seals, as well as loose screws that may cause damage to the machine.

 

(4) Environmental protection

The system incorporates a pulse dust collector for efficient dust capture and utilizes a silencer to effectively reduce noise, thereby demonstrating its environmental protection and cleanliness features.

 

Clirik is a reputable manufacturer of mining machinery and equipment, renowned for their global popularity. If you have any interest in our top-notch equipment, please feel free to contact us using the information provided on this page. Moreover, we boast a team of highly skilled engineers and technicians who are capable of tailoring machinery and equipment to meet your specific requirements, ensuring that they perfectly suit your needs. We eagerly await your call!