How To Choose A Right Kiln For Your Lithium Battery Material Production Line?

The selection of calcination equipment has an important impact on the performance and efficiency of lithium battery materials production process. Common calcination equipment includes rotary kilns, pusher kilns, hearth roller kilns, etc. These devices have characteristics and are suitable for different material and process requirements. How to choose the most suitable lithium battery material machiney for yourself? As an expert in lithium battery material production equipment, we have 20+years of experience in kiln production to help you better understand the differences between these kilns and their suitable application areas. Let’s learn together!

Rotary kiln

Lithium battery material rotary kiln is a heat treatment equipment widely used in the cathode material manufacturing plant and anode materials manufacturing plant for lithium batteries. Its structure is long cylindrical, and continuous rotation can be carried out inside to evenly heat the materials.

Features of rotary kiln

• Continuous production: Rotary kiln is a type of continuous calcination equipment, where the cylinder can rotate and the material continuously rolls inside the kiln to ensure uniform heating. It is particularly suitable for large-scale production and can work continuously for a long time.
• Atmosphere and temperature control: Rotary kilns have extremely high flexibility in temperature and atmosphere control, and can provide different atmosphere environments (such as oxygen or inert gases) to meet the different sintering needs of cathode and anode materials. The temperature control range is wide (600 ℃ -1000 ℃), suitable for the calcination of cathode and anode materials.
• Strong material adaptability: Rotary kilns are suitable for a variety of materials, whether they are granular, powdery, or block materials of different specifications, and can effectively process them. This has significant advantages in sintering positive electrode materials (such as NCM, NCA, LFP) and anode material (such as graphite, silicon-based materials) for lithium batteries.
• Good uniformity: The rotating function of the rotary kiln allows the material to continuously roll in the high-temperature zone, resulting in uniform heating and avoiding local overburning or undercorning.

Advantage of rotary kiln

• Suitable for large-scale production: The large capacity and continuity of rotary kilns make them an ideal choice for mass production, meeting the growing demand of the lithium battery industry.
• Uniform temperature distribution: The continuous rolling of the material and the uniformity of heat transfer ensure the sintering effect of the material and improve the electrochemical performance of the product.
• High flexibility: The atmosphere and temperature adjustment of the rotary kiln are flexible, and can adapt to sintering processes of different materials.

Disadvantages of rotary kiln

• Relatively high energy consumption: Rotary kilns have high overall energy consumption due to their large size and long-term operation characteristics.
• Large footprint: Due to the long length of the equipment, it occupies a relatively large factory area.

Pusher Kiln

Pusher kiln or pusher plate kiln is an continous kiln with multiple push plates to continuously push materials forward. Mainly used for sintering of cathode active materials for lithium batteries.

Features of pusher kiln

• Batch production: The pusher kiln is an continous production equipment, in which materials are roasted through the kiln chamber under the push of the push plate. Its temperature control accuracy is high, suitable for small and medium-sized production needs.
• Temperature and atmosphere control: The pusher kiln has high temperature control accuracy, which is suitable for material roasting that requires precise temperature curve control. It can provide specific temperature and atmosphere conditions at different stages, especially suitable for sintering lithium battery cathode materials with extremely high temperature control requirements, such as lithium iron phosphate (LFP) materials.
• High heat transfer efficiency: Due to the static transmission of materials on the push plate, the heat transfer efficiency is relatively high, which can achieve fast heating and cooling rates, suitable for materials with special requirements for heating and cooling rates.

Advantages of pusher kiln

• High precision temperature control: The pusher kiln can achieve extremely high temperature control accuracy, especially suitable for materials that are extremely sensitive to temperature requirements, such as the sintering of positive electrode materials.
• Flexible atmosphere control: The pusher kiln can control the atmosphere in sections, suitable for process requirements that require roasting under different atmospheres.
• Efficient heat transfer: The static push plate design makes the contact between the material and the heat source closer, resulting in higher heat transfer efficiency and saving some energy consumption.

Disadvantages of pusher kiln

• Not suitable for large-scale continuous production: The processing capacity of the push plate kiln is relatively small, and it is usually produced intermittently, which cannot meet the needs of large-scale production.
• Long occupation of manual operation time: Due to intermittent work, material loading and unloading require more manual intervention, and the degree of automation is relatively low.

Roller Hearth Kiln

Roller hearth kilns are also widely used in the production of lithium battery materials, especially in low-temperature calcination processes, suitable for heat treatment of cathode active materials and some high nickel systems.

Features of roller hearth kiln

• High temperature sintering: Roller kilns are equipment designed specifically for high-temperature sintering, and materials are transported through roller conveyors. It is suitable for high-temperature sintered materials that require precise temperature control, such as lithium battery cathode materials.
• Continuous production: Roller kilns can achieve continuous production, suitable for medium batch production needs. The materials are continuously transported along the kiln chamber on the roller conveyor, ensuring a stable and efficient production process.
• Accurate control of atmosphere: The atmosphere control of roller kilns is also very flexible, providing suitable oxygen or inert gas environments for each process stage.

Advantagesof roller hearth kiln

• Efficient production: The design of the roller kiln enables materials to quickly pass through the sintering zone, with a shorter roasting cycle and higher production efficiency.
• High temperature control accuracy: able to accurately control the temperature and atmosphere at different stages, suitable for materials with strict sintering process requirements.
• High degree of automation: The material transportation and sintering process of the roller kiln are fully automated, reducing manual intervention and improving production stability.

Disadvantages of roller hearth kiln

• Roller wear: Due to the material being transported through the roller conveyor, the roller conveyor is prone to wear or deformation at high temperatures, resulting in increased maintenance costs.
• Limited production capacity: The size of the roller kiln body limits the processing capacity, making it difficult to adapt to large-scale production.

Comparison of rotary kiln, pusher kiln and roller hearth kiln