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Precision Aluminum Nickel Composite Sheet Al/Ni For 18650 And 21700 Battery Welding
Engineered for reliable dissimilar metal joining, DLX precision aluminum nickel composite sheet (Al/Ni clad) provides atom-level interfacial bonding, ultra-low contact resistance, and zero delamination for 18650 and 21700 battery tab welding.
- Overview
- Specifications
- Features
- Applications
- About DLX
- FAQ
- Recommended Products
Product Overview: Engineered Bimetal Transition for Weld Reliability
In high-precision battery module assembly and power electronics packaging, direct welding between aluminum battery cases/terminals and nickel/copper busbars inevitably produces brittle intermetallic compounds (IMC) and high interface resistance. DLX precision Al/Ni composite sheets eliminate this failure mode by serving as an intermediate metallurgical bridge: manufacturers can weld aluminum-to-aluminum on the cell side and nickel-to-nickel on the busbar side using standard spot, ultrasonic, or laser welding equipment.
Manufactured via continuous solid-phase roll-bonding and proprietary atmosphere diffusion heat treatment, our Al/Ni composite strip features clean internal microstructures, uniform cladding layer ratios across both longitudinal and transverse directions, and burr-free slit edges suitable for continuous automated high-speed stamping and battery pack assembly lines.
Technical Specifications
Layer Materials & Cladding Configuration
| Layer Configuration | Material Grade / Alloy | Pure Metal Content | Function in Battery Assembly |
|---|---|---|---|
| Nickel Layer (Ni) | Pure Nickel N6 / Ni201 | ≥ 99.60% Ni | Spot / laser welding to nickel & copper busbars |
| Aluminum Layer (Al) | High-Purity Aluminum 1060 / 1050 | ≥ 99.60% Al | Ultrasonic / laser welding to aluminum cell casing/terminals |
| Bonding Interface | Solid-Phase Metallurgical Diffusion | 100% Metal Bond | Zero micro-voids, no brittle intermetallic phase |
Cladding & Mechanical Performance
| Parameter | Benchmark Specification | Test & Quality Verification Condition |
|---|---|---|
| Interfacial Bonding Strength | ≥ 120 N/mm (No delamination) | 90° & 180° continuous bending / peeling test |
| Thermal Shock Resistance | No layer separation or cracking | Thermal cycling between -40°C and +150°C |
| Tensile Strength (Annealed) | 120 – 210 MPa | Composite state tensile testing |
| Elongation (A50) | ≥ 18% | Deep drawing and 90° terminal bending |
| Micro-Hardness (Ni Layer) | 90 – 130 HV | Precision micro-indentation test |
| Micro-Hardness (Al Layer) | 25 – 45 HV | Precision micro-indentation test |
Electrical & Physical Properties
| Property | Metric Value | Engineering Significance |
|---|---|---|
| Electrical Contact Resistance | Ultra-low (Atom-level interface) | Prevents localized joule heating during rapid discharge |
| Electrical Conductivity (IACS) | ≥ 55% – 60% (Composite dependent) | High current density transfer in battery modules |
| Thermal Conductivity | High efficiency heat dissipation | Rapid heat conduction away from battery terminals |
| Density (1:1 Ratio) | ~5.80 g/cm³ | Significant weight reduction compared to pure nickel |
Supply Formats & Manufacturing Dimensions
| Supply Format | Thickness Range | Width Range | Thickness Tolerance | Surface Finish |
|---|---|---|---|---|
| Precision Clad Coil / Strip | 0.10 mm – 0.50 mm | 2.0 mm – 150.0 mm | ±0.008 mm to ±0.015 mm | Bright, smooth, degreased, oil-free |
| Ultra-Thin Foil Gauge | 0.08 mm – 0.12 mm | 3.0 mm – 80.0 mm | ±0.005 mm | Cleanroom packed, high formability |
| Stamped Battery Tabs / Blanks | Custom per drawing | Custom per drawing | ±0.02 mm stamping | Precision deburred, ready for automated welding |
Key Features & Advantages
100% Metallurgical Solid-Phase Bond with Zero Delamination
DLX Al/Ni composite sheets are processed under high-pressure cold roll bonding followed by continuous atmospheric diffusion annealing. This creates a genuine atomic-level metallurgical bond between aluminum and nickel, completely preventing layer peeling, edge separation, or micro-cracks during high-speed progressive die stamping and repetitive thermal cycling.
Prevention of Brittle Intermetallic Compound (IMC) Formation
Direct welding between aluminum and nickel creates brittle Al3Ni2 and Al3Ni phases that increase joint resistance and cause sudden weld fractures. Our pre-bonded composite material allows homogenous welding (Al-to-Al and Ni-to-Ni), guaranteeing high mechanical pull-test strength, low contact resistance, and long-term joint integrity.
Ultra-Tight Gauge Tolerances for High-Speed Automated Stamping
Utilizing high-precision multi-roller cold rolling mills, our Al/Ni composite strips maintain thickness tolerances down to ±0.008 mm. Combined with precision rotary shear slitting, edge burr height is tightly restricted to ≤ 0.01 mm, protecting progressive stamping tools and preventing cell separator damage during automated assembly.
Optimized Weight Reduction and Electrical Transfer Efficiency
By replacing heavy pure nickel busbar connections with lightweight Al/Ni clad material, overall battery pack connection weight is reduced by up to 35% without sacrificing current-carrying capacity, supporting energy density optimization in EV and portable energy storage systems.
Industrial Product Applications
18650 & 21700 Cylindrical Battery Pack Terminals
Used as the critical positive-to-negative terminal connection tabs and busbar bridge ribbons in high-rate 18650 and 21700 cylindrical lithium-ion battery modules for power tools, electric two-wheelers, and portable power stations.
Electric Vehicle (EV) Traction Battery Modules
Applied as flexible transition connectors between aluminum battery module cases/busbars and external nickel/copper terminals, maintaining high vibration resistance and electrical stability under demanding automotive driving conditions.
Commercial & Industrial Energy Storage Systems (ESS)
Integrated into containerized energy storage racks, high-capacity battery clusters, and uninterruptible power supplies (UPS) to manage high continuous discharge currents with minimal thermal buildup.
Consumer Electronics and High-Drain Cordless Appliances
Serving as lightweight, ultra-thin internal battery connection tabs in cordless vacuum cleaners, high-power drones, smart home devices, and wearable electronics.
Why Choose DLX Alloy
Complete In-House Metallurgical Cladding Control
DLX Alloy operates an integrated manufacturing base covering raw strip surface pretreatment, high-tonnage precision roll cladding, continuous vacuum diffusion heat treatment, multi-stand finishing rolling, and optical-guided rotary slitting. Every batch is tracked to maintain strict chemical, metallurgical, and dimensional uniformity.
Strict Defect-Free Quality Assurance Protocol
Every master coil undergoes multi-stage non-destructive testing and destructive validation, including 180° continuous bend/peel testing, micro-resistance interfacial measurement, metallographic cross-section microscopy, and high-precision laser thickness scanning.
Rapid Prototyping and Custom Stamping Capabilities
In addition to standard slit coils, DLX provides dedicated in-house precision die tooling and high-speed stamping presses. We deliver customized battery tab shapes, punched holes, and stepped terminal geometry samples in 3–7 business days to accelerate customer R&D cycles.
Dedicated Technical Support for Battery Welding Optimization
Our metallurgical engineering team works directly with B2B battery pack designers to determine the ideal cladding ratio (1:1, 1:2, or 1:3), optimize strip temper, and recommend optimal ultrasonic, laser, and resistance spot welding parameters for maximum production yields.
Product FAQ
Q1: Why is an Al/Ni composite sheet required for 18650 and 21700 battery tab welding instead of a pure nickel strip?
A1: Cylindrical cells like 18650 and 21700 frequently use aluminum casings or aluminum positive terminal caps. Directly welding pure nickel to aluminum creates brittle Al-Ni intermetallic compounds that suffer from high electrical resistance and premature joint failure under thermal/vibrational stress. The Al/Ni composite sheet provides an aluminum layer to weld cleanly to the cell terminal, and a nickel layer to weld to the external nickel/copper busbar, achieving high-reliability homogenous welds on both sides.
Q2: What cladding ratios are available, and how do I select the right one for my battery pack design?
A2: DLX supplies Al/Ni composite strips in standard thickness ratios of 1:1, 1:2, and 1:3 (Nickel : Aluminum), as well as custom asymmetrical configurations. A 1:1 ratio is widely used for standard resistance spot welding, while 1:2 and 1:3 ratios (with a thicker aluminum layer) provide higher electrical conductivity and superior weight savings for high-drain power tool and EV battery packs.
Q3: Which welding processes are recommended for the aluminum and nickel sides of the composite sheet?
A3: The aluminum layer is optimized for ultrasonic metal welding and fiber laser welding to cell terminals. The nickel layer is fully compatible with conventional resistance spot welding, micro-TIG, and laser welding to busbars. Our oil-free, degreased surface finish ensures clean, spatter-free weld nuggets with high tensile pull-test values.
Q4: Can DLX supply custom pre-punched tabs and stamped shapes according to engineering drawings?
A4: Yes. In addition to continuous slit coils, DLX operates in-house precision stamping and die-cutting facilities capable of producing custom battery tabs with specific terminal holes, stepped offsets, stress-relief slots, and multi-point contact tabs per your CAD drawings.
Q5
Q5: What are your commercial terms regarding Minimum Order Quantity (MOQ), lead time, and packaging?
A5: We offer low-threshold trial order MOQs (from 5 kg for standard stock gauges) and rapid prototype sample delivery in 3–7 business days. Standard export packaging utilizes anti-oxidation wrapping, moisture-barrier vacuum foil, desiccants, and reinforced seaworthy wooden cases for secure global air and ocean transport.
