Korean cathode makers automate single-crystal calcination lines to secure yields

South Korean cathode active material manufacturers are accelerating the automation of high-temperature calcination lines for high-nickel single-crystal chemistries, deploying enclosed continuous roller hearth kilns and robotic material handling to eliminate atmospheric moisture exposure and stabilize production yields. POSCO Future M, EcoPro BM, and LG Chem are directing process engineering capital toward the thermal synthesis stage, where tight atmospheric isolation and precise temperature uniformity determine product consistency for high-voltage nickel-cobalt-manganese (NCM) and nickel-cobalt-manganese-aluminum (NCMA) formulations.

Single-crystal cathode materials synthesize nickel, cobalt, and manganese precursors with lithium compounds into monolithic, single-grain particles rather than agglomerated polycrystalline clusters. Under high-pressure electrode calendering and repeated charge-discharge cycles, traditional polycrystalline cathodes develop internal microcracks that expose fresh particle surfaces to liquid electrolytes, accelerating transition metal dissolution, gas generation, and cell swelling. Single-crystal structures eliminate intergranular boundaries, allowing electric vehicle battery cells to operate safely at higher cutoff voltages and deliver extended cycle life.

Synthesizing single-crystal particles requires prolonged heat treatment in continuous roller hearth kilns (RHK) at operating temperatures ranging between 700 and 900 degrees Celsius, followed by micro-milling and secondary surface coating. This extended thermal profile increases per-kilogram electricity consumption and exposes vulnerable high-nickel compounds to ambient humidity during transfer stages. High-nickel cathode precursors and sintered intermediates absorb airborne moisture and carbon dioxide, generating residual lithium hydroxide and lithium carbonate on particle surfaces that impair electrochemical performance and cause battery pouch deformation.

To insulate cathode materials from seasonal humidity and reduce labor-intensive handling, Korean producers have automated the entire kiln loading and sagger transport sequence. POSCO Future M has integrated automated guided vehicles (AGVs), enclosed sagger conveyer tracks, and automated raw material feeding systems at its Gwangyang and Pohang manufacturing facilities. The company began mass-producing 86 percent nickel NCMA single-crystal cathode materials at its Gwangyang plant in 2023, supplying the product to Ultium Cells, the battery joint venture between General Motors and LG Energy Solution. Sintering furnace equipment specialist Wonjoon has supplied specialized roller hearth kilns to POSCO Future M to ensure uniform thermal distribution across multi-tiered saggers inside the continuous heating tunnel.

EcoPro BM has commercialized high-nickel single-crystal cathode formulations with nickel content reaching 88 percent, deploying automated calcination technology developed in partnership with industrial equipment manufacturer Hanwha Momentum. Hanwha Momentum supplies continuous roller hearth kilns equipped with automated crucible handling and precision oxygen atmosphere injection systems that prevent temperature variations across the calcination cross-section. By isolating the precursor-lithium mixture inside hermetically sealed conveyance loops and controlling the dry oxygen purge rate, EcoPro BM limits surface side reactions during the firing cycle without requiring excessive post-calcination chemical washing.

LG Chem operates a dedicated single-crystal cathode production setup that utilizes a bimodal particle distribution method. The company combines large-particle single crystals, which account for 70 to 80 percent of the cathode blend, with small-particle single crystals comprising the remaining 20 to 30 percent. This bimodal blending maximizes volumetric tap density while mitigating the slower lithium-ion diffusion kinetics typically associated with large single crystals. LG Chem executes a two-stage calcination process comprising primary high-temperature crystal growth, precision de-agglomeration milling, surface dopant application, and secondary low-temperature protective layer firing.

For global automotive original equipment manufacturers and Tier-1 battery cell producers, the operational efficiency of single-crystal calcination lines directly determines supply availability and procurement economics. Extended kiln residence times and higher energy inputs historically placed single-crystal cathodes at a cost premium over standard polycrystalline grades. Enclosed process automation addresses this cost penalty by raising first-pass synthesis yields, minimizing sagger contamination, and reducing the frequency of kiln shutdowns caused by thermal stress or uneven loading.

Industrial equipment makers Wonjoon and Hanwha Momentum continue supplying advanced continuous furnace lines to Korean production clusters as domestic cathode capacity expands. POSCO Future M is expanding its total cathode manufacturing footprint toward 106,000 metric tons per year in Pohang alongside its 142,500 metric ton site in Gwangyang. EcoPro BM and LG Chem maintain scheduled commercial shipments of bimodal and ultra-high-nickel single-crystal products to global cell customers across North American and European manufacturing corridors.