Wuxi Zhanghua: Empowering High-Purity Production of Ternary Precursors with Filtration-Washing-Drying "3-in-1" Equipment Ternary precursors—nickel-cobalt-manganese or nickel-cobalt-aluminum hydroxides—are the critical intermediates for lithium-ion battery cathode materials. A well-known saying in the industry goes: "The precursor quality determines 80% of the cathode material's performance ceiling." This is no exaggeration. Particle size distribution, sphericity, specific surface area, crystal structure—t

Wuxi Zhanghua: Empowering High-Purity Production of Ternary Precursors with Filtration-Washing-Drying "3-in-1" Equipment

Ternary precursors—nickel-cobalt-manganese or nickel-cobalt-aluminum hydroxides—are the critical intermediates for lithium-ion battery cathode materials. A well-known saying in the industry goes: "The precursor quality determines 80% of the cathode material's performance ceiling."

This is no exaggeration. Particle size distribution, sphericity, specific surface area, crystal structure—these indicators directly determine the cathode material's tap density, rate capability, and cycle life. Consequently, most R&D resources in the industry are concentrated on the co-precipitation reaction stage—precisely controlling the ratios of nickel, cobalt, and manganese to achieve atomic-level homogeneous co-precipitation under ammonia complexation and sodium hydroxide precipitation.

But one fact is severely underestimated: co-precipitation only builds the "morphological skeleton" of the precursor. What truly determines the final grade is the post-treatment stage—filtration, washing, and drying.

After co-precipitation reaction and aging, the precursor slurry requires solid-liquid separation, deep washing to remove impurity ions, and low-temperature drying. This process faces three core challenges:

Challenge One: The Trade-off Between "Depth" and "Efficiency" in Impurity Removal

The synthesis mother liquor contains large amounts of SO₄²⁻, Na⁺, NH₄⁺, and other impurity ions. Typical specifications require SO₄²⁻≤2000ppm and Na⁺≤200ppm. These ions exist not only in the mother liquor but also adsorb onto particle surfaces and within micropores. Surface rinsing cannot reach the adsorbed ions deep within micropores.

Conventional centrifuges or plate-and-frame filter presses use displacement washing, where fresh wash liquid follows the path of least resistance through the filter cake, creating a "channeling effect." The result: most wash liquid flows uselessly through cracks while impurities deep in the micropores remain untouched. To meet impurity targets, operators increase wash cycles and water consumption—but even then, washing efficiency remains low and wastewater volume is enormous.

Challenge Two: Particle Integrity Is Difficult to Preserve

Ternary precursor particles have relatively low mechanical strength, especially immediately after co-precipitation. The centrifugal force of high-speed centrifuges, and the mechanical shear forces during scraper discharge, can cause particle breakage, surface wear, or reduced sphericity.

For high-nickel products (NCM811, NCA), even minor damage to particle morphology is inherited by the cathode material, affecting subsequent sintering behavior and ultimately electrochemical performance. A damaged spherical particle becomes an irreparable defect after sintering.

Challenge Three: The "Sensitivity" of High-Nickel Systems Is Severely Underestimated

High-nickel precursors are extremely sensitive to oxygen, CO₂, and moisture. This is not a matter of "careful operation"—it is a fundamental chemical reality:

· Dissolved oxygen in wash water oxidizes Mn²⁺ to form MnOOH impurities—one impurity phase means product downgrade

· Atmospheric CO₂ reacts with particle surfaces to form carbonate impurities—severely impacting first-cycle coulombic efficiency

· High-temperature drying can trigger surface oxidation or excessive dehydration—irreversible structural changes

The common root cause: material exposure to non-protective environments throughout the process. A single exposure is enough to downgrade an entire batch.

Wuxi Zhanghua's Filtration-Washing-Drying "3-in-1" equipment integrates solid-liquid separation, displacement washing, and vacuum drying within a single closed vessel. This is not simple functional stacking—it is a fundamental change in how impurities are removed.

Efficient Washing: Slurry Washing vs. Displacement Washing

The core differentiator of the 3-in-1 is its "slurry washing" function. Through the rotating motion of the agitator, the filter cake and wash liquid are fully mixed and dispersed within the closed vessel, forming a suspension. In this state, impurity ions adsorbed on particle surfaces and within micropores are fully dissolved into the wash liquid.

The equipment then applies pressure or vacuum for filtration, discharging the wash liquid containing dissolved impurities. This "slurry-filtration" cycle can be repeated multiple times, each providing full contact across all material and all surfaces—no channeling, no dead zones, no shortcut-taking by wash liquid.

The results: less wash liquid consumption, more thorough impurity removal, and lower wastewater volume.

Gentle Drying: Vacuum Low-Temperature Preserves Particle Integrity

The 3-in-1 performs drying under vacuum at low temperatures. The vacuum environment lowers the boiling point of water, enabling drying at temperatures typically 20-30°C lower than atmospheric drying. For high-nickel precursors, this directly translates to lower surface oxidation risk and more complete particle morphology preservation.

For high-nickel products, the equipment can be configured with an inert atmosphere protection system, supplying nitrogen or argon throughout vacuum drying to ensure Ni²⁺ is not oxidized to Ni³⁺. Protecting the stoichiometric ratio at the molecular level is a core process requirement for premium precursors.

Fully Closed Operation: Eliminating Contamination at the Source

The 3-in-1 completes filtration through drying entirely within a closed vessel—no material transfer, no exposure.

This means:

· Dissolved oxygen in wash water is removed in advance (via nitrogen sparging), eliminating Mn²⁺ oxidation

· Atmospheric CO₂ cannot contact particle surfaces, preventing carbonate impurity formation

· Ambient moisture and particulates cannot enter the system, ensuring batch purity

Precision Filtration and Automatic Discharge: Improving Yield and Consistency

Equipped with high-precision filter cloth or sintered metal filter media (filtration accuracy down to 1-5μm), ensuring complete solid-liquid separation and high solid recovery.

Equipped with automatic hydraulic discharge mechanism, ensuring smooth discharge with minimal residue, reducing batch-to-batch variation caused by manual operation.

Comparison Dimension Conventional Centrifuge + Dryer 3-in-1 Equipment

Washing Method Displacement washing, severe channeling Slurry washing, full contact all surfaces

Washing Efficiency Low, high water consumption High, significantly reduced water usage

Washing Uniformity Non-uniform, dead zones present Uniform and thorough, no dead zones

Material Exposure Multiple transfers, high exposure risk Fully closed, zero exposure

Particle Protection Centrifugal force + transfer damage Gentle operation, no mechanical damage

Automation Level Segmented operations, labor-dependent Fully automated, consistent batch quality

High-Nickel Adaptability Difficult to achieve inert atmosphere protection Configurable for inert atmosphere, high-nickel ready

Audit Traceability Segmented records, difficult to trace Full process parameter logging, complete traceability

High-purity production of ternary precursors depends not only on precise control during co-precipitation reaction, but equally on the purity assurance and particle protection capabilities of the post-treatment stage. These two stages are equally critical—neither can be compromised.

Wuxi Zhanghua's Filtration-Washing-Drying "3-in-1" equipment, with its fully closed integrated design, efficient slurry washing capability, gentle vacuum drying method, and stringent material and surface finish standards, provides critical process assurance for high-purity ternary precursor production.

Founded in 1976, Wuxi Zhanghua has been dedicated to the R&D and manufacturing of core process equipment—reaction, crystallization, filtration, and drying—for nearly five decades. With extensive experience in specialty materials including Hastelloy, titanium, and PTFE/PFA lining, and international certifications including ASME, CE, PED, and ATEX, Wuxi Zhanghua has delivered a range of validated 3-in-1 equipment solutions to the new energy materials sector, enabling customers to achieve stable, high-purity ternary precursor production at scale.

When impurity targets tighten from 2000ppm toward 500ppm, and particle size distribution narrows from ±5μm toward ±1μm—choosing a 3-in-1 is not about "better equipment." It's about "a higher process ceiling."

 Technical Inquiry： ZhangPeijie@zhanghuayaoji.com

 Website： www.zhanghua1976.com