New energy vehicles demand for precision stamping parts
New energy vehicles, battery cases, lightweight, precision stamping, automotive supply chain, electric drive systems, thermal management
The global automotive industry is experiencing a power system transformation unseen in a century. The penetration rate of new energy vehicles (NEV) has climbed from less than 5% in 2020 to more than 35% in 2025, and even exceeded 50% in the European and Chinese markets in stages. This structural transformation has a profound and multi-dimensional impact on the hardware stamping industry. It not only reshapes the category map of stamping parts, but also puts forward jumping requirements for materials, precision and process reliability. This paper analyzes how new energy vehicles can become the demand engine for precision stamping parts from four key modules: battery system, electric drive system, body lightweight and thermal management system.
Battery Pack Case: Stamped "New World"
The power battery pack is the core and most valuable incremental assembly for new energy vehicles. The market for its shell stamping parts has jumped from almost zero to tens of billions of dollars. The battery shell is divided into three parts: the battery shell, the module frame and the whole package lower shell. The battery shell usually adopts a precision deep drawing process, using nickel-plated steel strip or aluminum alloy strip with a thickness of 0.3mm to 0.8mm, which has extremely strict standards for wall thickness uniformity, air tightness and surface cleanliness. Taking the 4680 large cylindrical battery shell as an example, its depth-diameter ratio exceeds 1:2.5, and the traditional multi-station stretching is prone to bottom fracture or wall wrinkle. It is necessary to introduce the flexible speed curve and partition blank holder force control of the servo press to control the failure rate below 50 ppm.
As a structural protective part, the lower shell of the battery pack was welded by dozens of stamping parts in the early days, and is now evolving towards integrated large-scale stamping. The aluminum alloy integrated lower shell adopts 6000 series or 7000 series plates, and is formed by multi-station continuous die or series stamping line. The stamping depth can reach more than 200mm, which puts forward extremely high requirements for the cooling water channel design and thermal balance management of the die. At the same time, in order to meet the IP67/IP69K sealing grade of the battery pack, the flatness and hole accuracy of the flange surface of the shell need to reach less than 0.1mm, which promotes the deep coupling of the large-tonnage servo punch and the online laser measurement system. Global major battery manufacturers are cultivating their own stamping supply chains or building their own internal stamping capacity to ensure the safety and consistency of shell supply.
Electric drive system stamping parts: the challenge of high precision and high speed
The electric drive system replaces the engine and gearbox of the fuel vehicle, which brings a series of stamping parts requirements such as the motor stator and rotor core, reducer gear, inverter shell and connecting copper bars. Among them, the motor stator and rotor core is laminated from 0.25mm to 0.35mm thick non-oriented silicon steel sheets, and the stamping accuracy directly affects the efficiency of the motor. Silicon steel sheet stamping belongs to the category of high-speed micro-stamping. The stamping times are usually 400 to 800 times per minute. The edge clearance of the die needs to be controlled within 3% -5% of the material thickness, and the burr height should not exceed 0.02mm. As the speed of the drive motor moves towards more than 20000rpm, the requirements for the lamination coefficient and coaxiality of the iron core are increasingly stringent, which drives the iterative upgrade of precision progressive die and online stacking riveting technology.
The inverter housing is usually made of aluminum alloy die-casting, but the internal busbar, shield and cooling plate are heavily stamped. Copper busbar stamping requires a very high surface finish and edge chamfering to prevent high voltage discharge. Some high-performance models even use oxygen-free copper for micro-stamping, and the thickness accuracy requires ±0.01mm. This poses a significant challenge to the consistent control of the stamping process.
Body lightweight: The stamping race for aluminum and hot-formed steel
The anxiety of new energy vehicles about the cruising range drives the lightweight of the body to a deeper level. The application ratio of aluminum sheets in four doors, two covers, fenders and other cover parts has risen rapidly from less than 10% of fuel vehicles to 30% -50%. The difficulty of aluminum alloy stamping lies in its low n-value and r-value, narrow forming window and significant rebound. At present, aluminum sheet cover parts mainly use servo punches with multi-action air cushions, which avoid cracking and wrinkling through variable pressure control during stretching. Aluminum plate hot forming-hardening (HFQ) technology has also been mass-produced in some high-end models. The strength of parts can reach more than 250 MPa, and the rebound is controlled within 0.2mm.
In the field of body safety structural parts, hot-formed boron steel (PHS) continues to expand its position. New energy vehicles have a very low tolerance for side impact intrusion due to the fact that the battery is arranged under the floor, which forces B-pillars, threshold beams, and side anti-collision beams of battery packs to use a large number of 1500MPa or even 2000MPa hot-formed steel. The hot stamping production lines for such parts are highly automated, including heating furnaces, fast-conveying manipulators, servo hydraulic presses, and in-mold quenching systems, and the investment in a single production line can easily exceed 100 million yuan. Between 2024 and 2025, China will add more than 60 hot stamping production lines, more than half of which will serve new energy vehicles.
Thermal management system stamping parts: the mastermind behind precise temperature control
The thermal management system of new energy vehicles is far more complex than that of fuel vehicles, involving multiple circuits such as battery cooling, motor cooling, passenger compartment heat pump, and power electronic heat dissipation. This system has spawned a large number of stamped cooling plates, runner plates, and water chambers. Such parts are usually stamped with stainless steel or aluminum alloy sheets and brazed with another stamped part, laser welded, or friction stir welded to form a sealed runner. The stamping process requires strict control of burrs and deformation to ensure the smoothness of the welding surface and the consistency of the runner section. As the battery fast charging power moves towards 800V or even higher, the heat dissipation density of the liquid cooling plate increases sharply, and the geometric accuracy of the stamping runner evolves from the sub-millimeter level to the micron level, which promotes the stamping process to the direction of etching + stamping composite process.
The reshaping of the supply chain landscape
The demand for precision stamping parts in new energy vehicles is reshaping the supplier pyramid. Traditional Tier 1 stamping giants are accelerating the transformation of electrified product lines, while a number of Technologically Advanced Small and Medium-sized Enterprises focusing on battery cases and electric drive stamping parts are rapidly emerging. In order to ensure the core element of battery safety, automakers are increasingly choosing to deeply bind with stamping suppliers, and even adopt the "factory-in-a-factory" model, requiring stamping lines to be built directly inside the battery factory. This trend of vertical integration has set new standards for the delivery response speed and quality management system of stamping enterprises, and has also spawned a new round of capital investment and technology competition in the stamping industry.
