As lithium-ion batteries pursue higher initial Coulombic efficiency and longer service life, small-particle cathode lithium supplements such as Li5FeO4, which has a theoretical specific capacity of 867 mAh/g, have progressed from laboratory research to commercial-scale applications. However, their drying processes face three core challenges:
(1) Particle-size control versus crystal protection
Conventional atomizers struggle to reduce droplets to the submicron scale, while high-temperature drying can cause an imbalance between Fe2+ and Fe3+ valence states and affect lithium-extraction efficiency.
(2) Uniformity versus production efficiency
Open drying systems are prone to introducing impurities, and particle-size distributions can become uneven during batch production, resulting in poor battery consistency.
(3) Energy costs versus environmental requirements
High-purity protection and efficient dust removal create dual requirements that drive up energy consumption in conventional equipment, with product costs exceeding RMB 2,000 per metric ton.
As a front-runner in China’s new energy drying equipment sector, Jiangsu Longxin Drying focused on the principle of “nanoscale activity with micron-scale application” for lithium supplements. After three years of development, the company has introduced its third-generation ultra-high-speed centrifugal spray dryer for small-particle cathode lithium supplements. Through breakthroughs in three core modules—atomization, thermal-field control, and process control—the system supports a new drying approach characterized by precise particle size, intact crystal structure, and efficient, environmentally responsible operation, helping customers gain an edge in a highly competitive market.
Core Technology Breakthroughs: Three Keys to Drying Small-Particle Lithium Supplements
(1) Ultra-high-speed atomization: From droplet breakup to customized particle size
Longxin has independently developed an ultra-high-speed centrifugal atomizer and optimized it through CFD simulation, achieving three major advances in the atomization process:
Uniform microdroplets:
The impeller edge uses a variable-curvature design. Under centrifugal force on the order of 105 g, the feed forms a film only 50–100 μm thick. When the film breaks up, it forms microdroplets with a controlled average droplet-size standard deviation.
Viscosity adaptability:
For high-solids slurries such as a mixed LiOH and FeC2O4 slurry with 40% solids content, a guide cone at the center of the impeller helps reduce slurry-transport resistance and the frequency of clogging.
Wide particle-size adjustment range:
By adjusting impeller speed from 8,000 to 20,000 rpm and feed pressure from 0.2 to 0.5 MPa, the system can precisely control the particle size of the dried ultrafine powder. This covers the requirements of mainstream lithium supplements, including Li5FeO4 at 0.8–2.6 μm and Li2MnO3 at 1–3 μm.
(2) Gradient thermal-field drying: Balancing crystal protection and moisture removal
Lithium supplements tend to absorb moisture at low temperatures and undergo phase changes at high temperatures. To address these characteristics, Longxin designed a staged thermal-field control strategy:
Preheating zone (upper tower):
The inlet-air temperature is set at 250–300°C to rapidly evaporate surface moisture, which accounts for approximately 60% of total moisture. This helps prevent abrupt particle-size changes caused by uneven surface tension in the droplets.
Constant-temperature zone (middle tower):
The temperature is maintained at 180–220°C. A spiral airflow promotes the inward diffusion of moisture, helping prevent the formation of hollow structures with a hardened outer shell and residual moisture inside.
Cooling zone (lower tower):
A low-temperature air curtain helps prevent internal stress caused by excessive temperature differences after drying, supporting the integrity of the crystal structure.
(3) Full-process intelligent control: From experience-based operation to data-driven operation
Self-optimizing control system:
An intelligent algorithm uses historical production data to automatically recommend optimal process parameters, helping improve the product yield achieved by less-experienced operators.
Energy management system:
Variable-frequency drives dynamically adjust fan power, while waste-heat recovery reduces the equipment’s overall energy consumption.
Technical Details: Optimizing the Microscopic Performance of Lithium Supplement Drying
(1) Key atomizer parameters
| Parameter | Conventional Equipment | Longxin Equipment | Technical Advantage |
|---|---|---|---|
| Impeller material | 316L stainless steel | TC4 titanium alloy | Improved wear resistance and longer service life |
| Speed adjustment range | 8,000–15,000 rpm | 8,000–20,000 rpm | Improved precision of particle-size adjustment |
| Atomization method | Single-channel centrifugal atomization | Dual-channel spiral centrifugal atomization | Improved processing capability for high-viscosity slurries |
(2) Optimized drying-tower design
Cone angle:
A 55° cone bottom extends the particle residence time inside the tower, allowing more complete moisture evaporation.
Internal surface treatment:
The inner-wall surface roughness is Ra ≤ 0.4 μm, and a nanoscale ceramic coating is applied to key areas to reduce material loss and cleaning costs.
Gas–liquid contact area:
By jointly optimizing the atomizer height and inlet-air distributor angle, the gas–liquid contact area is increased by 15% and mass-transfer efficiency by 10% compared with conventional equipment.
(3) Clean production safeguards
High-efficiency fresh-air filtration:
A natural-gas-fired hot-air generator combined with three-stage air filtration provides high air cleanliness and helps prevent impurity introduction.
Dead-corner-free design:
All material-contact components are precision-polished to a surface roughness of Ra ≤ 0.4 μm, supporting rapid cleaning.
Low dust emissions:
The bag filter uses PTFE membrane filter media with a 0.5 μm rating and a pulse-jet reverse-cleaning system operating at 0.6 MPa, supporting zero dust escape.
Choose Longxin: The Optimal Solution for Small-Particle Lithium Supplement Drying
As the new energy industry enters an era of micron-level competition, the technical precision of drying equipment directly determines product competitiveness. Centering on ultra-high-speed centrifugal atomization technology, Jiangsu Longxin Drying has established a complete technology chain covering material-property analysis, process-parameter design, customized equipment manufacturing, and full-lifecycle service. The company provides drying solutions for small-particle cathode lithium supplements with controllable particle size, intact crystal structure, high efficiency, and low energy consumption.
Every small technical improvement can translate into a meaningful capacity gain in a battery’s charge–discharge curve, and every improvement in production efficiency can create tangible cost advantages for customers. Longxin Drying is more than an equipment manufacturer; it is a technology partner for advanced energy-material preparation. From laboratory development to industrial production, we work alongside our customers, using professional expertise and innovation to advance lithium battery technology.
