Answer: It is core equipment in lithium battery electrode manufacturing. It delivers precise, stable rolling force via a servo hydraulic system to drive a pair of high-precision work rolls for continuous compaction of coated electrode sheets, processing electrodes to the target thickness. It is critical for improving battery energy density and ensuring electrode consistency.

Answer: It is located after the electrode coating process and before the electrode slitting process, as a key mid-stage process in electrode manufacturing. Its core function is to compact the active material layer with controllable pressure to boost electrode energy density and adhesion between active material and current collector, while ensuring uniform thickness to supply qualified substrates for subsequent slitting, winding and stacking.

Answer: ① Higher pressure control accuracy: servo hydraulics enable linear pressure regulation with minimal fluctuation, adaptable to electrodes of various specifications. ② Wider pressure output range: meeting calendering demands for wide-format, high-compaction-density power batteries. ③ Flexible buffering: absorbing impact from incoming thickness fluctuations, protecting roll surfaces and electrodes for high-precision mass production.

Answer: Core units include: unwinding unit, automatic web guiding unit, tension control unit, calendering mainframe (work rolls, back-up rolls, servo hydraulic system, roll gap adjustment mechanism), on-line thickness measurement unit, winding unit, electrical control system, and safety protection system. Optional configurations include heating system, dust removal system and surface detection module.

Answer: It directly impacts energy density, internal resistance & rate performance, cycle life, batch consistency and safety. Insufficient compaction reduces energy density; excessive compaction damages material structure and worsens electrolyte wettability. Uneven thickness causes uneven internal cell reactions, intensifies polarization, and degrades consistency and safety.

Answer: Standard process: incoming electrode unwinding → automatic edge position correction → constant tension control → surface dust removal before rolling → roll gap pre-positioning → servo hydraulic calendering → real-time on-line thickness detection → post-rolling tension buffering → winding edge correction → neat winding under constant tension. The whole process realizes closed-loop feedback adjustment of roll gap, pressure and tension.

Answer: For mainstream precision models, machine direction (along web travel) thickness accuracy reaches ±0.5~±1μm, and cross direction (along roll width) thickness accuracy reaches ±1~±2μm. High-end power battery lines with closed-loop thickness systems can further improve consistency. Actual accuracy also depends on incoming areal density fluctuation and roll surface precision.

Answer: For high-precision work rolls, full-face radial runout ≤ 0.001mm (1μm), and roll surface cylindricity ≤ 0.001mm/m. The roll body uses alloy forged steel base with hard chrome plating or tungsten carbide coating. Surface hardness reaches HRC 62~68, and surface roughness Ra ≤ 0.02μm, balancing precision and wear life.

Answer: Consumer battery models typically run at 30~80m/min; power battery models commonly run at 60~150m/min, and high-speed mass production models can exceed 200m/min. The speed ceiling is limited by substrate strength, compaction density requirements, thickness accuracy requirements, thickness gauge response speed, and capacity matching with upstream/downstream processes.

Answer: Depending on roll width and model grade, maximum linear pressure per roll commonly ranges 100~800kN/m, and wide-format power battery models can exceed 1000kN/m. The servo hydraulic system achieves pressure control accuracy within ±0.5% FS, and supports free switching between constant pressure and constant roll gap modes.

Answer: Precision servo hydraulic models achieve roll gap adjustment accuracy of ±0.1μm with response time ≤ 10ms. Combined with closed-loop feedback from on-line thickness measurement, it quickly corrects deviations from incoming thickness fluctuations and avoids batch thickness defects in continuous production.

Answer: Machine direction uniformity is mainly affected by incoming areal density fluctuation, hydraulic pressure stability, web tension fluctuation and line speed variation. Cross direction uniformity is mainly affected by work roll crown design, roll surface temperature uniformity, roll gap parallelism, and incoming CD areal density difference.

Answer: The mainstream X-ray/laser on-line thickness gauge has measurement accuracy of ±0.1μm and sampling frequency up to kHz level. It collects real-time post-calendering thickness data, feeds back to adjust roll gap and hydraulic pressure for dynamic thickness correction, and generates thickness reports for quality traceability and process optimization.

Answer: There are three core reasons: ① It enables high-precision dual closed-loop control of pressure and position, meeting the strict precision requirements of electrode compaction. ② Hydraulic transmission has high power density, delivering high compaction force for wide-format electrodes in a compact structure. ③ It provides overload protection and flexible buffering, reducing roll surface damage risk from foreign objects in incoming materials.

Answer: Hydraulic oil viscosity changes with temperature. Temperature fluctuation causes unstable pressure and flow, directly impairing calendering accuracy and thickness consistency. Excessively high oil temperature also accelerates seal aging and increases leakage risk. Normal operating temperature is recommended at 35~55℃, with a standard water/air cooling system keeping temperature fluctuation ≤ ±2℃.

Answer: Unstable tension causes web deviation, wrinkling and breakage, and also leads to uneven MD thickness and inconsistent elongation, ultimately degrading cell dimensional accuracy and performance consistency. Precision models achieve tension control accuracy of ±1% FS via full closed-loop control, adaptable to electrodes of different thicknesses and materials.

Answer: The mainstream system uses photoelectric/ultrasonic sensors to detect electrode edge position, and drives a servo actuator to adjust web position in real time in a full closed loop. Guiding accuracy typically reaches ±0.1~±0.3mm, ensuring neat winding and avoiding uneven edge thickness or equipment damage from web misalignment.

Answer: It is equipped with an accumulator pressure-holding mechanism, emergency pressure relief circuit and mechanical locking device. During power failure, the accumulator maintains system pressure to prevent sudden roll gap closure that would crush the electrode; the emergency circuit slowly releases pressure and lifts work rolls. Mechanical safety pins lock the roll gap during maintenance to prevent misoperation.

Answer: It supports lithium-ion cathodes (LFP, NCM/NCA, LCO, etc.) and anodes (artificial graphite, natural graphite, silicon-based anode, etc.). For current collectors, it works with 6~12μm copper foil and 10~20μm aluminum foil. It is also compatible with new electrodes such as sodium-ion and solid-state battery electrodes by adjusting process parameters.

Answer: Incoming coated electrode thickness is typically 80~500μm, and double-sided areal density ranges 100~500g/㎡. For width, consumer-grade models adapt to 100~600mm, and power-grade models adapt to 600~1400mm. Exact compatibility shall be confirmed based on roll face length and pressure specifications.

Answer: All standard models support continuous double-sided calendering, which is the mainstream production configuration. Precautions: ① Ensure double-sided areal density consistency to avoid post-calendering warpage. ② Match rolling pressure and speed to material characteristics. ③ Use multi-pass calendering for high-compaction-density electrodes to prevent shedding and cracking from excessive single-pass reduction.

Answer: Wrinkling causes: uneven tension, poor roll gap parallelism, incoming warpage, unparallel guide rolls, failed web guiding. Solutions: optimize tension parameters, calibrate roll gap parallelism, adjust inlet angle, inspect guide rolls and guiding system. Breakage causes: excessive pressure, incoming damage/joints, sudden tension change, foreign object jamming. Solutions: reduce rolling pressure, inspect incoming quality, stabilize tension, install foreign object detection.

Answer: Cold calendering is the industry mainstream, suitable for most conventional cathode/anode electrodes, with simple structure, low O&M cost and high efficiency. Hot calendering models heat work rolls (typically 60~150℃), suitable for high-compaction-density electrodes, thick electrodes or low-binder-activity systems. Hot rolling improves material ductility and reduces material shedding and cracking, yet consumes more energy and requires stricter process control.

Answer: ① Hydraulic system: check oil level, oil temperature and pipeline leakage. ② Roll surface: inspect scratches, foreign matter and stains, clean rolls thoroughly. ③ Safety components: verify emergency stops, safety door interlocks and safety light curtains. ④ Calibration status of tension and guiding sensors. ⑤ Power supply, air source and cooling system. ⑥ Smooth rotation of unwinding/winding shafts and guide rollers.

Answer: Slight wear or tiny scratches: online polishing and grinding to restore surface roughness. Moderate damage: disassemble the rolls for re-chroming or tungsten carbide spraying, followed by precision grinding to recover accuracy and hardness. Severe scratches or roll crown deformation: replace with brand-new work rolls. Control foreign objects and install dust removal to extend roll service life.

Answer: Follow the sequence from simple to complex: ① Check and calibrate thickness gauge to eliminate zero drift. ② Verify hydraulic pressure stability between set value and actual value. ③ Calibrate roll gap zero point and roll parallelism. ④ Confirm incoming areal density and thickness meet process standards. ⑤ Check matching of tension and line speed parameters. ⑥ Inspect roll surface wear and failure of roll crown compensation.

Answer: Typical leakage locations: aging cylinder seals, loose pipe joints, defective valve seals, high oil temperature accelerating seal degradation. Solutions: ① Stop machine and release pressure to locate leaks, tighten loose connectors. ② Replace aged seals with matched specifications. ③ Maintain proper oil temperature via cooling system. ④ Replace hydraulic oil and filters periodically to avoid seal abrasion from oil impurities.

Answer: ① Hydraulic oil & filter elements: replace every 6~12 months. ② Seals for hydraulic cylinders and valves: inspect and replace every 2~3 years. ③ Roll cleaning rubber rollers: replace every 3~6 months. ④ Tension & guiding sensors: regular calibration, replace every 3~5 years upon wear. ⑤ Work roll surface coating: chrome coating serves 2~3 years; tungsten carbide coating lasts 5~8 years; repair or replace according to actual abrasion.

Answer: Safety door with mechanical interlock, safety light curtains at inlet and outlet, multi-point emergency stop buttons, hydraulic overload protection, electrical overcurrent & overheat protection, web break detection stop device, mechanical roll gap safety lock, warning lights and buzzers. Optional extras include automatic roll lifting for foreign object detection, fire detection and suppression systems, complying with lithium production safety standards.

Answer: ① Process parameters: electrode type (cathode/anode), incoming thickness & areal density, target compaction density, electrode width, target line speed and thickness precision requirements. ② Optional functions: hot calendering, online thickness measurement, dust removal, surface inspection. ③ Site conditions: workshop layout dimensions, power capacity, cooling water and compressed air supply. ④ Compatibility: multi-specification electrode adaptability and future capacity expansion potential.