Introduction

The iteration of new energy batteries is essentially an iteration of materials. From graphite to silicon-carbon, from lithium-ion batteries to sodium-ion batteries, every breakthrough in anode materials redefines the ceiling of energy density. In the preparation process of these high-performance anode materials, sintering—a seemingly traditional process—plays a crucial role in determining the final performance of the material.

Recently, we successfully delivered three customized dual-purpose Vacuum/Atmosphere Sintering Furnaces to a customer in the new energy battery anode material field. This equipment adopts a unique "dual-function" design, with a single power cabinet alternately driving two independent furnace bodies, while each furnace body has an ultra-large high-temperature zone loading space of 3 cubic meters (700×700×6000mm). Their deployment will provide a solid guarantee for the efficient, stable, and high-quality production of porous carbon anode materials.

I. Technological Depth: Why is Vacuum/Atmosphere Sintering Essential for Porous Carbon Anodes?

Porous carbon materials (such as hard carbon and biomass-derived carbon) are currently core candidate materials for sodium-ion batteries and next-generation lithium-ion battery anodes. Their advantages include: high specific surface area providing abundant sodium/lithium storage sites; unique pore structure buffering volume expansion during charge and discharge; and a three-dimensional conductive network ensuring rapid electron transport.

However, to accurately achieve these characteristics, the sintering process must simultaneously meet two stringent conditions:

1. Absolute protection by an inert atmosphere: During carbonization, if the precursors of porous carbon (such as resins, straw, and nutshells) come into contact with oxygen, they will either oxidize and lose weight or burn and become unusable. Therefore, the entire sintering process must be carried out under the protection of high-purity nitrogen or argon. The airtightness of the furnace and the purity of the atmosphere directly determine the product yield and consistency.

2.Vacuum-assisted pore formation: Simple static atmosphere sintering often fails to achieve the ideal pore structure. During the heating process, a vacuum system is introduced to promptly extract gases generated from precursor pyrolysis (such as CO₂, water vapor, and tar gas) at specific stages. This operation effectively prevents pore blockage caused by gas retention, helping the material form an open, interconnected pore network, thereby precisely controlling the specific surface area and pore size distribution.

This delivered Vacuum/Atmosphere dual-purpose Sintering Furnace is designed to meet the aforementioned core process requirements.

II. Equipment Highlights: One-to-Two + Spacious Design, Redefining Production Efficiency

The three machines delivered this time are not traditional single units, but a system integrating efficiency, stability, and process flexibility. Its design fully considers the customer's dual needs for large-scale production and process consistency.

1. Innovative "One-to-Two" Architecture

In anode material production, the sintering process is often the bottleneck of the entire production line. Traditional single-power-supply, single-furnace mode results in long heating, holding, and cooling cycles, limiting equipment utilization.

Our one-to-two Sintering Furnace adopts a design where "one power cabinet controls two independent furnace bodies." The two furnace bodies can operate in staggered shifts: when one furnace body is in a critical heating or holding stage, the other can perform loading/unloading or cooling operations. This design nearly doubles power utilization, maximizing production capacity without increasing investment in power distribution facilities. For customers, this means achieving higher daily output with less equipment footprint and lower unit energy consumption.

2.  3 Cubic Meters of Extra-Large Loading Space

The high-temperature zone of each furnace body measures 700mm (width) × 700mm (height) × 6000mm (length), with an effective volume of 3 cubic meters. This long furnace design is particularly suitable for continuous, long-stroke charging of porous carbon material precursors. Whether using a boat-propelled production method or loading large tooling fixtures, the 6-meter uniform temperature zone ensures consistent temperature across the entire batch of material in the axial direction. For anode material production where batch stability is crucial, the long furnace combined with high uniformity directly translates into improved product yield.

3. Wide Window Reserved for Complex Processes

Temperature Uniformity: For the large 3-cubic-meter space, the equipment utilizes multi-zone independent temperature control technology to ensure that the temperature difference between any two points within the furnace is controlled within an extremely narrow range. This is critical for porous carbon materials—only under uniform temperature conditions can the density and carbonization degree of the entire furnace material remain highly consistent.

Safety Interlocks: Porous carbon precursors release flammable gases (such as methane and tar vapor) during carbonization. The equipment is equipped with comprehensive overpressure relief, inlet protection, and exhaust gas treatment interfaces to ensure the safe and controllable operation of the high-temperature degreasing and carbonization processes.

III. Application Value: How to Empower Anode Materials for New Energy Batteries?

The value of this Sintering Furnace ultimately lies in the performance of the customer's products. Specifically, it contributes to the quality improvement of porous carbon anode materials in three aspects:

1. Improved Conductivity and Reduced Internal Resistance

High-temperature carbonization is a process of carbon atom rearrangement and the formation of a conductive network. The equipment's precise temperature control capability can stabilize the carbonization temperature within the optimal range, allowing the material to achieve a suitable degree of graphitization, ensuring good electronic conductivity without excessively damaging the pore structure. This ultimately translates to lower DC internal resistance (DCIR) and better rate performance in the battery.

2. Optimized Structural Stability and Extended Cycle Life

During the sintering process, the coordinated regulation of vacuum and atmosphere—for example, maintaining a slight negative pressure state within a specific temperature range—effectively removes gases generated by precursor decomposition, preventing internal stress concentration. This "gentle venting" process helps form a dense and structurally stable carbon skeleton, making it less prone to pulverization during hundreds or even thousands of charge-discharge cycles, significantly extending battery life.

3. Customized Pore Adjustment for Enhanced Capacity

The equipment offers a wide process adjustment window for different precursors (such as phenolic resin and coconut shell). From room temperature to maximum operating temperature, from high vacuum to micro-positive pressure, from static atmosphere to dynamic airflow—customers can flexibly adjust the sintering process according to the characteristics of their own materials, achieving precise control over the contrast surface area and pore size distribution, thereby obtaining higher reversible capacity and first-pass yield.

IV. Conclusion: Leveraging Equipment to Drive Materials Innovation

The successful delivery of 3units of One-to-Two Vacuum/Atmosphere Sintering Furnaces is more than just a simple equipment delivery; it represents a profound empowerment of the new energy battery industry chain.

At this crucial stage of transitioning porous carbon anode materials from the laboratory to large-scale mass production, stable, efficient, and process-adaptable thermal equipment is the cornerstone of ensuring product consistency and cost competitiveness. We are honored to participate in this process, using our solid equipment technology to help our customers gain a competitive edge in cutting-edge fields such as sodium-ion batteries and semi-solid-state batteries.

If you are also looking for specialized equipment suitable for sintering porous carbon, hard carbon, and silicon-carbon anode materials, please feel free to contact us. We look forward to discussing process solutions with you and jointly promoting technological advancements in new energy battery materials.