High-Compaction Density LFP Spray Drying Technology — Case Study of Jiangsu Xinpu Drying

I. Case Overview

Jiangsu Xinpu Drying Engineering Technology Co., Ltd. has conducted in-depth research on the characteristics of high-compaction density lithium iron phosphate (LFP) materials, and independently developed a new ultra-fine powder spray dryer tailored for high-compaction LFP. The equipment meets the stringent requirements of LFP materials in terms of particle size, sphericity, and compaction density.

Successfully deployed in multiple domestic high-compaction LFP projects, the equipment has achieved breakthroughs in overcoming the limitations encountered by conventional spray dryers. It delivers precise control over product particle size specifications — the product D50 can reach two specifications of 20–30 μm and 5–10 μm, with high sphericity and solid spherical particles, resulting in significantly improved compaction density.

Currently, Xinpu Drying has the manufacturing capability for ultra-large spray drying towers with a diameter of up to 18 meters, with a single-line annual black powder production capacity of up to 130,000 tons, demonstrating the large-scale and scaled-up development level of domestic lithium battery material spray drying equipment.

II. Case Details

Jiangsu Xinpu Drying Engineering Technology Co., Ltd. has conducted in-depth research on the characteristics of high-compaction density lithium iron phosphate materials, and independently innovated and developed a new ultra-fine powder spray dryer suitable for high-compaction LFP. The equipment can meet the high requirements of LFP for particle size, sphericity, and compaction density, achieving breakthroughs in solving the difficulties encountered by conventional spray dryers. It delivers precise control over product particle size specifications — the product D50 can reach two specifications of 20–30 μm and 5–10 μm, with high sphericity and solid spherical particles, and the compaction density is improved compared with products produced by conventional equipment.

The new spray dryer has been continuously improved in terms of energy utilization efficiency, drying effect, and automation level, and can better meet the production needs of high-compaction density LFP batteries. In 2025, Xinpu Drying successfully delivered two large-scale LFP spray dryers to leading lithium battery material enterprises. Each drying tower has a diameter of 16 meters and a spray liquid processing capacity of 45 tons per hour, achieving an annual black powder production capacity of over 100,000 tons per production line. Currently, the company has the capability to manufacture ultra-large spray drying towers with a diameter of 18 meters, with a single-line annual black powder production capacity of up to 130,000 tons. The equipment has been successfully applied in multiple domestic high-compaction LFP projects.

III. Key Delivery Metrics of Xinpu Drying High-Compaction Projects

IV. Working Principle of High-Compaction LFP Spray Dryer

(1) Feed Liquid Atomization

LFP slurry is conveyed by a variable-frequency feed pump to the high-speed centrifugal atomizer at the top of the dryer. The atomizer rotates at very high speeds (up to 25,000 rpm). Under centrifugal force, the feed liquid is flung out from the edge of the atomizer, stretched, torn, and broken into extremely fine mist droplets. This greatly increases the contact area between the feed liquid and hot air, laying the foundation for subsequent efficient drying.

(2) Hot Air Supply and Contact

Air is purified through a filtration device to remove impurities and dust, ensuring the purity of the drying process. The filtered air is heated to a set temperature (140°C–350°C, adjustable according to material characteristics and drying requirements), and enters the drying chamber uniformly in a spiral pattern through Xinpu's independently developed special hot air distributor, where it makes co-current contact with the mist droplets ejected from the atomizer.

(3) Moisture Evaporation and Drying & Solidification

After the mist droplets come into contact with the hot air, due to the enormous surface area of the droplets, the hot air can rapidly evaporate and carry away the moisture in the droplets. For feed liquids with a moisture content of 60%–80%, drying and solidification are typically completed within seconds, forming powder products with uniform particle size and compact structure. No secondary treatment is required, greatly improving production efficiency.

(4) Finished Product Collection

The dried LFP particles move downward with the airflow to the bottom of the drying tower and enter the baghouse dust collector. In the baghouse, solid particles are separated from the gas through the filtering action of filter bags. The separated LFP finished product particles are collected, and the exhaust gas is discharged through an induced draft fan. The dry powder recovery rate is ≥95%.

V. Technical Advantages of High-Compaction LFP Spray Dryer

(1) High Drying Efficiency

Rapid atomization: The high-speed centrifugal atomizer can rapidly convert LFP feed liquid into very fine mist droplets, greatly increasing the surface area of the feed liquid and geometrically multiplying its contact area with hot air. Feed liquid with 60%–80% moisture content can be dried into powder products within seconds without secondary treatment, significantly improving production efficiency.

Uniform drying: Hot air enters the drying chamber uniformly in a spiral pattern and makes co-current contact with the mist droplets, ensuring that each droplet can fully and uniformly exchange heat with the hot air. This avoids incomplete local drying or over-drying, guaranteeing the drying quality of the product.

(2) Controllable Particle Size Distribution

Adopting a high-speed centrifugal atomizer with flexibly adjustable rotation speed (11,000–25,000 rpm) according to material characteristics, combined with an optimized atomizing disc design, precise control over product particle size is achieved, ensuring LFP particles have good uniformity and sphericity. The product D50 can reach two specifications: 20–30 μm and 5–10 μm.

The particles feature high sphericity and are solid spheres. Compared with the irregular hollow spheres produced by conventional spray dryers, they offer better flowability and dispersibility, with significantly improved compaction density.

(3) Ultra-Large Tower Body Design

The drying tower can reach a maximum diameter of 18 meters, with single-line capacity exceeding the industry's conventional level. The delivered equipment has a single-unit diameter of 16 meters, a spray liquid processing capacity of 45 tons per hour, and an annual black powder production capacity of over 100,000 tons, meeting the large-scale and continuous production needs of major lithium battery material manufacturers.

Relying on the 268-mu Langxi base, 45,000 m² heavy-duty workshop, and 100T/50T crane cluster, parallel manufacturing of ultra-large equipment is supported.

(4) High Cleanliness Design

The drying chamber is made of mirror-finish stainless steel plates, welded under argon protection, with the inner surface polished to Ra ≤ 0.8 μm — smooth, flat, and free of dead corners. Copper/zinc-free at contact surfaces, with Cu+Zn <1% at non-contact surfaces, meeting the mandatory high-purity access thresholds for power battery materials.

The atomizer adopts a unique labyrinth seal structure to prevent lubricating oil leakage and product contamination, and is equipped with quick-open cleaning ports for easy disassembly, assembly, and cleaning.

(5) Anti-Wall-Stick Optimization

Based on precise calculation of the atomization angle of the atomizer, the drying chamber diameter is appropriately enlarged to prevent material from sticking to the wall during the pre-drying process. The cone angle of the discharge cone is optimized to 50° and equipped with pneumatic rappers to ensure smooth discharging without material accumulation.

The bottom of the drying tower adopts a flow deflector design to prevent material deposition; it is equipped with a reliable cold air and bypass system to protect the safe operation of the baghouse dust collector.

(6) Excellent Product Quality

The drying process takes place in a closed system, reducing material contact with outside air and effectively preventing impurity contamination. Special systems such as nitrogen closed-loop circulation further ensure product purity. The particles have uniform size and compact structure, with good flowability and dispersibility, which helps improve the material's tap density and battery energy density.

(7) Intelligent Automation Control

Equipped with an advanced PLC control system with interlock program control. Operators only need to set process parameters such as feed speed, atomizer speed, and drying temperature, and the equipment will automatically complete the drying process. The variable-frequency control of the feed pump is interlocked with the exhaust air temperature to automatically adjust operating parameters. Process parameters can be flexibly adjusted within a certain range to meet diverse production requirements.

(8) Energy Saving and Environmental Protection

Some equipment is equipped with waste heat recovery devices that recycle and reuse the waste heat generated during the drying process, improving energy utilization efficiency. It is equipped with efficient dust removal devices such as pulse dust collectors to effectively collect drying dust and reduce dust emissions. Closed-system drying reduces material contact with outside air. The equipment has strong applicability and can be horizontally migrated to applications such as sodium batteries and battery recycling black powder.

VI. High-Compaction Technology Breakthroughs

High compaction density is one of the core indicators of LFP cathode materials, directly affecting the energy density and charge-discharge performance of lithium batteries. Xinpu Drying has achieved multiple key breakthroughs in the preparation process of high-compaction density LFP:

1. Solid Sphere Particle Preparation

By optimizing the atomizing disc design and rotation speed control, the dried LFP particles are solid spheres. Compared with the hollow sphere particles produced by conventional equipment, solid spheres have higher tap density and compaction density, directly improving the compaction density of battery electrodes.

2. Support for Two Particle Size Specification Controls

Precise control of product D50 at two specifications — 20–30 μm and 5–10 μm — is achieved, which is finer than the 30–50 μm particle size range of conventional equipment. A finer and more uniform particle size distribution contributes to tight packing between particles, having a significant effect on improving compaction density.

3. Independently Developed Hot Air Distributor

Absorbing advanced foreign technology and independently improving the design, hot air enters the drying tower uniformly through a special distribution structure, effectively preventing turbulence and chaotic flow, eliminating drying dead corners, and ensuring consistency of the material drying environment, providing stable process guarantee for high-compaction density products.

4. High Sphericity Assurance

The LFP particles produced by the equipment have high sphericity. Compared with irregular spherical shapes, high sphericity gives the material better flowability and solubility, and enables tighter packing between particles, significantly improving electrode compaction density and battery energy density.

VII. Technical Parameters

VIII. Market Advantages of Xinpu Drying High-Compaction Projects

(1) Technical Advantages

Outstanding particle size control: The new LFP ultra-fine powder spray dryer developed by Xinpu Drying performs well in product particle size control, achieving product D50 of 20–30 μm / 5–10 μm — two specifications that are finer than domestic conventional spray dryers (conventional product D50 is 30–50 μm). Finer particle size control helps improve the performance of LFP materials and meets market demand for high-end materials.

High sphericity: The equipment can produce solid spherical LFP products with high sphericity. Compared with the irregular hollow spheres produced by conventional spray dryers, the improved sphericity gives the material better flowability and solubility, with significantly enhanced compaction density, which has positive implications for subsequent battery production and other application links.

Large production capacity scale: Xinpu Drying's new equipment has delivered single-unit towers with a diameter of 16 meters, a spray liquid processing capacity of 45 tons per hour, and an annual black powder production capacity of 100,000 tons. The maximum manufacturing capacity reaches 18 meters in diameter, with an annual black powder production capacity of up to 130,000 tons — far higher than the 100–1,000 kg/h evaporation rate of conventional equipment — capable of meeting large-scale production demands.

High clean manufacturing standards: Copper/zinc-free at contact surfaces, Cu+Zn <1% at non-contact surfaces, and inner wall Ra ≤ 0.8 mirror polishing, meeting the mandatory high-purity access thresholds for power battery materials. There are relatively few manufacturers in the industry that can simultaneously undertake towers of this scale while ensuring metal contamination prevention.

(2) Company Strength and Qualifications

Strong comprehensive strength: Xinpu Drying is a comprehensive enterprise integrating design, manufacturing, R&D, and service of drying and calcination equipment. The company covers an area of 268 mu, with a workshop area of over 85,000 m², including over 45,000 m² of heavy-duty workshops, over 20 sets of 100-ton/50-ton cranes, and over 200 sets of various precision manufacturing and monitoring equipment.

Complete qualification certifications: The company holds an A2-class pressure vessel manufacturing license and has passed the American ASME certification. It is a high-tech enterprise. With a registered capital of 25.8 million yuan, it currently employs over 200 people, including 32 technical R&D staff and 8 senior engineers.

Professional talent team: The company has a team of professionals with over ten years of experience in mechanical transmission and drying equipment industries, specializing in solution design, equipment structural design, processing technology design, electrical automation design, production scheduling management, and customer service.

Manufacturing asset base: The 268-mu Langxi base, 45,000 m² heavy-duty workshop, and 100T/50T crane cluster support parallel delivery of 16-meter-class and even 18-meter-class equipment. This heavy-asset manufacturing base imposes high requirements on manufacturing capability.

(3) Market Demand and Industry Development

Growing market demand: With the rapid development of the new energy vehicle market, the demand for lithium-ion batteries continues to increase, and the market demand for lithium iron phosphate — as a cathode material for lithium-ion batteries — is also growing rapidly. In particular, high-compaction density LFP is becoming the mainstream direction of the industry due to its higher energy density advantage.

Industry reputation and cooperation: With rich project design experience and good product performance, Xinpu Drying has accumulated a good reputation in the industry and established long-term cooperative relationships with many leading lithium battery material enterprises. Its products have been successfully exported to international markets including Europe.

Horizontal technology migration: The homologous large-scale centrifugal atomization and thermal technology can be horizontally migrated to sodium battery and battery recycling black powder tracks, opening up new growth ceilings. Enterprises that master 16-meter-class tower manufacturing bases and 100,000-ton-class process packages have high customer switching costs.

From "auxiliary machine" to "capacity determinant": The combination of 16-meter-class tower physical scale and 100,000-ton-class economic capacity scale marks that the LFP drying process has officially entered the "ultra-large single-line era". Equipment suppliers have transformed from production line supporting parties into important participants when customers calculate their "equipment investment accounts".

IX. Applicable Materials

Lithium iron phosphate (LFP), lithium titanate (LTO), and other lithium battery cathode and anode material slurries, as well as spray drying granulation of other solutions, emulsions, and suspension-type materials.

X. Reference Clients

The equipment of Jiangsu Xinpu Drying Engineering Technology Co., Ltd. has been successfully applied in multiple domestic high-compaction LFP projects, serving leading enterprises and multiple key enterprises in the lithium battery materials industry. With professional technical strength, excellent product performance, and comprehensive after-sales service, the company has established a good reputation and long-term cooperative relationships in the industry. Its products have been successfully exported to international markets including Europe.

Xinpu Drying has successively provided complete sets of equipment for many enterprises, including LFP spray dryer units, iron phosphate drying rotary kilns, iron phosphate rotary flash drying + rotary calcination kiln production lines, covering the complete industry chain of lithium battery cathode and anode materials, precursors, and battery recycling. The company is equipped with professional testing equipment and can provide incoming material testing and customized design services.

XI. About Xinpu Drying

Jiangsu Xinpu Drying Engineering Technology Co., Ltd. is a comprehensive enterprise integrating the design, manufacturing, R&D, and service of drying and calcination equipment. In 2024, Anhui Jinma Thermal Energy Equipment Co., Ltd. officially spun off its drying equipment division to establish Jiangsu Xinpu Drying Engineering Technology Co., Ltd., a private joint-stock enterprise.

Located in the center of the Yangtze River Delta — Langxi Industrial Park in the Jiangsu-Anhui Economic Cooperation Zone, adjacent to Changzhou — the company is approximately a one-hour drive from both Changzhou and Nanjing. With a registered capital of 25.8 million yuan, the company currently employs over 200 people, including 32 technical R&D staff and 8 senior engineers. The company covers an area of 268 mu, with a workshop area of over 85,000 m², including over 45,000 m² of heavy-duty workshops, over 20 sets of 100-ton/50-ton cranes, and over 200 sets of various precision manufacturing and monitoring equipment. The company holds an A2-class pressure vessel manufacturing license and has passed the American ASME certification.

Based in industries such as chemicals, new energy materials, catalysts, environmental protection, and fluorochemicals, the company builds on three main equipment categories — rotary kiln calciners, rotary flash dryers, and spray dryers — to provide integrated solutions from dehydration and drying to high-temperature calcination for powdery, granular, pasty, and liquid materials.

Translated from Chinese. Source: Jiangsu Xinpu Drying Engineering Technology Co., Ltd.