Prismatic Cell Aluminum Battery Case vs. Steel Case

China's new energy vehicle (NEV) sales grew 40% year-on-year in 2025 (per China Association of Automobile Manufacturers). Battery case materials have become a key focus. A prismatic cell aluminum battery case uses lightweight aluminum alloy. A steel case relies on high-strength steel. This article will compare their core performance, cost & process, environmental adaptability, application fields, and present Xiamen APOLLO's aluminum battery case solutions.

 

 

1. Weight and Energy Density​

The aluminum case weighs 30-40% less than a steel case of the same size. For a 70kWh NEV battery pack, using an aluminum case reduces the pack's total weight by 15-20kg. This directly improves the vehicle's range by 5-8%. It's a key advantage for NEVs that need long mileage.​

 

2. Strength and Impact Resistance​

Steel cases have higher tensile strength (500-600MPa) than aluminum cases (300-400MPa). But aluminum cases use alloy materials (e.g., 6061-T6). These materials absorb impact well. In NEV crash tests, an aluminum shell for lithium ion battery cell can withstand 15kN impact force. It won't crack and meets national safety standards.​

 

3. Corrosion Resistance​

Aluminum cases form a natural oxide film (Al₂O₃) on the surface. This film resists corrosion from battery electrolytes. A steel case needs extra galvanizing or painting. Without these treatments, it may rust in 2-3 years. For battery aluminum cases used in coastal areas, aluminum's corrosion resistance is 2x better than uncoated steel.

 

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1. Material cost: Aluminum alloy (for aluminum prismatic casing) costs 1.2-1.5x more per kg than cold-rolled steel. But aluminum cases are lighter. So the total material cost per battery pack is only 5-10% higher than steel cases.​

 

2. Processing difficulty: Steel cases need stamping and welding. The production cycle is 8-10 hours per unit. An aluminum shell for lithium ion battery cell uses extrusion and CNC machining. This process is more precise. It takes 6-8 hours-faster for mass production.​

 

3. Scrap rate: Steel case welding has a scrap rate of 5-7%. Weld cracks cause this high rate. Aluminum prismatic casing uses laser welding. Its scrap rate is only 2-3%. This lowers overall production costs.

 

 

Aluminum and steel battery cases serve different scenarios. Aluminum cases are mainly used in mid-to-high-end NEVs (e.g., Tesla Model 3, BYD Han). Their lightweight advantage makes this possible. They also fit portable energy storage devices. Weight reduction is critical for these devices. Steel cases are used in low-cost NEVs, electric two-wheelers, and mno2 battery case for household appliances. These scenarios care more about cost than weight. For industrial energy storage systems, battery aluminum cases are preferred. They have a longer service life (8-10 years vs. 5-6 years for steel cases).

 

 

1. High and Low Temperature Performance​

In -40℃ low-temperature environments, the aluminum case has a thermal conductivity of 200W/(m·K). This is 5x higher than a steel case. It helps the battery heat up faster. This ensures NEVs start normally in cold regions. In 85℃ high temperatures, aluminum cases don't deform. But steel cases may warp a little.​

 

2. Vibration Resistance​

Battery aluminum housing is used in commercial vehicles. These vehicles face frequent vibration. Aluminum has good ductility. It reduces vibration transmission by 30% compared to steel. This protects the battery cells inside from long-term vibration damage.​

 

3. Humidity Resistance​

In 90% RH humid environments, an aluminum shell for lithium ion battery cell stays intact after 1000 hours of testing. A steel case without anti-corrosion treatment shows rust spots after 500 hours. It needs more frequent maintenance.

 

 

Xiamen APOLLO's prismatic cell aluminum battery case uses high-quality 6061-T6 aluminum alloy. It has a tensile strength of 380MPa. It's 35% lighter than steel cases. Our product range includes aluminum prismatic casing and aluminum shell for lithium ion battery cell. All pass salt spray tests (1000 hours no rust) and impact tests (18kN no damage).​

 

We hold ISO9001-2015, IATF16949, and ROHS certifications. Our products meet GB/T 31486-2025 (China's prismatic battery case standard) and UL 94 standards. We offer custom services. We can adjust case size (length 100-500mm, width 50-200mm, height 20-80mm), wall thickness (1.5-3mm), and surface treatment (anodizing, powder coating). These adjustments fit NEVs, energy storage, or household appliances. Our global logistics covers air, land, and sea. Air shipping takes 3-5 days to Asian customers. Land shipping takes 7-15 days to Southeast Asia. Sea shipping takes 15-20 days to Europe and America. Our 24-hour after-sales team provides on-site installation guidance and quality inspection. We ensure each product meets customer requirements.