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In the dispersion of high solid content slurries, viscosity increases and fluidity decreases, making it prone to poor dispersion and variability. The movement of particles is restricted, making it difficult for aggregates to break apart, and it is not uncommon for undispersed areas to remain. Additionally, poor wetting during powder addition and the formation of localized high concentration areas can lead to the occurrence of clumps, which is another challenge. These issues may not be completely resolved even with strong shear applied in subsequent processes. What is important under such high solid content conditions is to efficiently transmit dispersion energy and standardize the processing conditions for each particle. However, in batch processing, variations in flow and residence time can lead to differences in the dispersion state. On the other hand, in inline continuous processing, uniform shear can be applied to particles within the flow, allowing for efficient transmission of dispersion energy even under high viscosity and high solid content conditions. This results in a uniform dispersion state for each particle, achieving stable quality. In the dispersion of high solid content slurries, it is crucial not only to apply strong shear but also to design the process considering flow and processing conditions. Inline processing is one effective method to address these challenges.

In dispersion engineering, challenges such as "clumps persist regardless of how many times conditions are changed" and "variability in particle size distribution does not improve" occur in many settings. In one case, the cause of poor dispersion was attributed to equipment performance, leading to responses such as increasing rotation speed and extending processing time. However, the persistence of clumps and variability in quality were not resolved, and rather, new problems arose, such as particle fragmentation due to excessive shear. Behind such failures lies the misconception that "dispersion = just apply strong shear." In reality, if clumps are formed in the initial stage due to poor wetting or uneven flow when the powder is introduced, it is difficult to completely resolve them by applying strong shear in subsequent processes. Additionally, in batch processing, variations in flow and residence time lead to different dispersion histories for each particle, making it impossible to ensure reproducibility of quality. To address this issue, it is crucial to review the entire process, including not just changes in equipment conditions but also the steps from powder introduction to dispersion. By adopting configurations that apply shear simultaneously with powder introduction and implementing inline continuous processing that maintains consistent flow and dispersion conditions, it is possible to suppress initial clumps and achieve stable dispersion quality. Improving poor dispersion requires optimization of the entire process, not just the equipment alone.

In the manufacturing process of battery material slurry, it is important to uniformly disperse multiple materials such as conductive materials, active substances, and binders. However, on-site challenges arise, including the residual aggregation of conductive materials, variations in particle size distribution, and instability in coating properties. These issues stem from differences in dispersion behavior due to material characteristics. In particular, carbon-based conductive materials are prone to aggregation and can form a network structure if insufficient shear is applied, leading to poor dispersion. Additionally, battery material slurries often have high solid content and high viscosity, which can lead to reduced fluidity and make it difficult for dispersion energy to be transmitted uniformly. Furthermore, poor wetting during powder addition and differences in mixing order can also affect the dispersion state and final quality. Even if dispersion can be achieved without issues in the lab, variations in flow conditions and shear history during mass production may prevent the reproduction of similar quality. To resolve these challenges, it is crucial to design dispersion conditions tailored to the characteristics of the materials and to optimize the entire process, including flow, shear, and residence time. In inline continuous processing, particles are treated under consistent conditions, which helps to minimize variations in dispersion history and achieve uniform and reproducible quality. The design of the dispersion process plays a vital role in stabilizing battery performance.

In dispersion processes, the variation in quality is one of the significant challenges. Even when processing under the same equipment and conditions, it is not uncommon for the dispersion state to differ from batch to batch. The main factor behind this is the variability in the dispersion history experienced by the particles. In batch processing, the shear and residence time experienced by each particle differ depending on their position and flow state within the tank. As a result, there is a mixture of sufficiently dispersed particles and undispersed particles, leading to variations in quality. This tendency becomes particularly pronounced under high viscosity or high solid content conditions. On the other hand, in continuous processing, particles pass through a consistent processing area, receiving nearly the same dispersion conditions. Because shear energy and residence time can be controlled consistently, the variability in dispersion history is minimized, resulting in a uniform and highly reproducible dispersion state. Moreover, continuous processing is advantageous during scale-up. By adjusting the flow rate, it becomes easier to replicate similar dispersion quality from the lab to mass production. This helps reduce the risk of quality fluctuations during the transition from development to mass production. What is crucial in dispersion processes is to provide the same processing history to all particles. Continuous processing easily meets this condition and is an effective method for stabilizing quality and ensuring reproducibility.

In dispersion processes, viscosity is an important factor that significantly affects dispersion efficiency. Generally, as viscosity increases, fluidity decreases, making it more difficult for dispersion energy to be transmitted to the particles. When viscosity is low, liquids flow easily, and shear energy is widely transmitted throughout the system, making it relatively easy to break apart particle agglomerates. On the other hand, as viscosity increases, flow becomes localized, and shear tends to be concentrated near the equipment. As a result, there is a mixture of particles that receive sufficient energy and those that do not, leading to variability in the dispersion state. Additionally, under high viscosity conditions, the movement of particles is also restricted, making collisions and breakdowns between agglomerates less likely. Consequently, even if the mixture appears homogeneous, there may be undispersed regions remaining internally. To enhance dispersion efficiency, it is crucial to implement appropriate shear conditions and flow designs according to viscosity. Particularly in inline continuous processing, it is possible to provide uniform shear to the particles within the flow, allowing for efficient transmission of dispersion energy even under high viscosity conditions. In dispersion processes, optimizing flow, shear, and processing time while considering the effects of viscosity is key to achieving stable dispersion quality.