Application Case of Electromagnetic Vibratory Feeders in the Production of Lithium‑Battery Cathode and Anode Materials

Summary

Lithium‑battery cathode materials—lithium iron phosphate, ternary materials, and their precursors—impose extremely stringent requirements on the precision and cleanliness of powder‑feeding equipment across processes such as batching, sintering and potting, pulverization and conveying, and finished‑product packaging. The AT BR FZH/FZL series electromagnetic vibratory feeders have been deployed in mass production lines at numerous leading lithium‑battery material manufacturers, covering the entire process—from precise metering and batching of precursors to high‑accuracy weighing and packaging of finished products. This paper presents the practical solutions and operational data for electromagnetic vibratory feeders in four core process stages.

Industry Background

Since the explosive growth of electric vehicles, global lithium‑battery production capacity has expanded nearly fivefold, with China accounting for more than 70% of that increase. Cathode materials—lithium iron phosphate (LFP), ternary materials (NCM/NCA)—and precursors represent the largest share of cell‑cost components and impose the most stringent requirements on powder‑handling equipment.

A common challenge with these materials is their high density, poor flowability, tendency to bridge, and sensitivity to metallic contaminants. Traditional conveying methods such as screw conveyors and belt conveyors struggle to simultaneously meet requirements for precision, cleanliness, and low maintenance costs. The ATBR FZH/FZL series electromagnetic vibratory feeders are specifically designed for such operating conditions.

Process Stages and Feed Requirements

1. Precursor Co-precipitation — Metered Dosing

Preparation process of ternary precursors: Solutions of nickel, cobalt, and manganese salts are continuously pumped into the reactor along with an alkaline solution and a complexing agent, with pH, temperature, and stirring speed all requiring strict control. After the reaction is complete, the resulting slurry undergoes filtration, washing, and drying; the recovered powder then proceeds to the next blending step.

Here lies a often-overlooked precision bottleneck: the metered feeding of dried precursor powder into the mixer. The precursor powder typically has a D50 particle size of 3–15 μm, with a high proportion of fine particles, making dust generation and wall adhesion commonplace.

The feed rate of the ATBR FZH series electromagnetic vibratory feeder is controlled by adjusting the coil current, with stepless regulation across the entire range. When paired with a load cell for closed-loop control, batch‑to‑batch batching accuracy can be maintained within ±0.5%. The vibrating trough is integrally formed from 304 stainless steel, with an interior wall polished to Ra ≤ 0.8 μm, significantly reducing powder adhesion to the walls.

2. Lithium iron phosphate sintering—loading into a saggar

The mainstream route for lithium iron phosphate is high-temperature solid-state synthesis: a lithium source (lithium carbonate or lithium hydroxide), an iron source (iron phosphate), and a carbon source are mixed in stoichiometric proportions, loaded into a crucible, and sintered at 700–800°C under nitrogen atmosphere.

In the crucible‑loading stage, uniformity is a critical quality criterion. If the loading thickness varies by more than 2 mm, products from the same batch will exhibit inconsistent sintering and scattered electrochemical performance. Manual loading or gravity‑fed feeding makes it difficult to ensure consistent results.

Our approach involves installing an array of FZH‑type electromagnetic vibratory feeders above the kiln‑car conveyor line, with one feeder assigned to each car position. A PLC issues unified control commands, enabling synchronized start‑up and shutdown of all feeders and ensuring strict consistency in the charge weight per car. The vibration frequency is 50 Hz, with an adjustable amplitude ranging from 0 to 2 mm, allowing the material to be evenly distributed through a gentle, micro‑suspension motion. Field tests on a 50,000‑ton‑per‑year production line demonstrated that the deviation in car‑loading thickness was kept within 1.5 mm.

3. Ternary cathode material—conveyed after air‑flow pulverization

After sintering, the ternary material is milled in an air‑flow mill to achieve the target particle size. The resulting powder has a relatively high temperature (approximately 60–80°C), and its increased specific surface area further degrades its flowability; therefore, it must be conveyed under sealed conditions to the subsequent coating or sieving processes.

Electromagnetic vibratory feeders have several inherent advantages at this location:

• The hopper can be fitted with a sealed cover and connected to a dust‑collection duct, enabling fully enclosed conveying that prevents dust from escaping and keeps foreign objects from entering.
• The material-contacting components contain no rotating parts, eliminating the risk of metal particles generated by bearing wear. This is particularly critical for ternary‑material batteries—excessive metallic contaminants are a common trigger for cell self‑discharge and even thermal runaway.
• The electromagnet and the trough are mounted separately, preventing heat from the material from reaching the coil; thus, prolonged continuous operation will not be compromised by temperature rise.

4. Finished-product packaging — high-precision weighing and dosing

Finished cathode materials are typically packaged in 25‑kg bags or in 500‑ to 1,000‑kg bulk bags. Today, customers’ requirements for net‑content accuracy are becoming increasingly stringent: for 25‑kg bags, tolerances are generally kept within ±50 g, and for bulk bags, within ±200 g—while maintaining a fast packaging throughput.

The ATBR FZL/FZH series (closed-type) operates in dual-speed feeding mode when paired with a weighing indicator:

This fast‑slow combination reduces the packaging time per bag to 15–20 seconds, while maintaining accuracy within ±30 g (for the 25 kg specification), so you don’t have to choose between efficiency and precision.

Technical Features

Metal foreign-object prevention and control.   All material-contact surfaces are constructed from 304 or 316L stainless steel; for high‑requirement applications, the interior can be lined with or coated by PTFE. The tank welds undergo pickling and passivation, virtually eliminating the risk of weld‑spatter shedding. If required, an online iron‑removal device can be integrated into the feeder to simultaneously capture any trace ferromagnetic particles that may inadvertently enter during conveyance.

Precise feeding and fast response.   The electromagnetic drive responds within 50 ms, with no start‑stop delay. The amplitude is linearly adjustable from 0 to 2 mm, and the feed rate can be precisely controlled down to the gram level. It supports PLC/DCS remote control and can be directly integrated into the production line’s automation system.

Low maintenance.   It has no rotating parts, no bearings, and no lubrication points; routine maintenance simply involves periodic cleaning of the trough. The electromagnet is designed for a service life exceeding 10 years and can operate continuously around the clock without issue. The leaf springs are made from a high‑strength carbon‑fiber composite material, with a fatigue life of over ten million cycles.

It can withstand harsh environments.   The FZL/FZH fully enclosed models can operate reliably in high-dust environments, with a protection rating of up to IP65. They are capable of handling material temperatures ranging from 60°C to 100°C. Explosion-proof versions are available to meet the safety requirements of lithium‑battery material processing facilities.

Conclusion

The production of lithium‑battery cathode and anode materials is simultaneously advancing in three key directions: higher capacity, stricter quality standards, and lower costs. Electromagnetic vibrating feeders have a simple structure yet deliver sufficient control precision, making them well suited for applications such as material batching, pot loading, post‑grinding conveying, and finished‑product packaging.

ATBR has been manufacturing electromagnetic vibratory feeders for many years, and the FZH/FZL series has been in operation on the production lines of numerous leading lithium‑battery material manufacturers for an extended period—our performance data speaks for itself. We don’t just sell equipment; we handle everything from equipment selection and installation to commissioning and integration with your production‑line automation—turnkey solutions from start to finish.

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