Flat Hydrogen Storage System for Fuel Cell Vehicles

BMW Group has introduced a new hydrogen storage system designed for integration into fuel cell electric vehicles, combining high-pressure storage, compact packaging, and production compatibility. The system is implemented in the BMW iX5 Hydrogen and targets long-range, fast-refuelling applications within a flexible automotive data ecosystem.

Storage architecture as a limiting factor in hydrogen mobility
In hydrogen fuel cell vehicles, storage design directly affects vehicle range, packaging efficiency, and safety. Conventional cylindrical tanks often constrain vehicle architecture, limiting integration with existing platforms.

The newly developed flat storage system addresses these constraints by reconfiguring tank geometry and system integration. It enables storage of approximately seven kilograms of hydrogen at 700 bar pressure, supporting a driving range of up to 750 km, while maintaining refuelling times below five minutes.

Multi-chamber high-pressure tank configuration
The system consists of seven carbon fibre-reinforced composite tanks connected in parallel and housed within a structural metal frame. Unlike traditional discrete tank layouts, the design links multiple chambers into a single controlled unit via a central valve system.

This multi-chamber configuration improves volumetric efficiency and allows more effective use of installation space within the vehicle floor. The structural integration also enhances mechanical protection by embedding the tanks within the vehicle architecture.

The use of carbon fibre-reinforced materials ensures high strength-to-weight ratio under 700-bar operating conditions, aligning with established standards for high-pressure hydrogen storage.

Integration into vehicle platform and powertrain
A key design objective is compatibility with existing vehicle architectures. The flat storage system is engineered to coexist with a high-voltage battery system, enabling hybridization within a fuel cell drivetrain.

This configuration supports a broader technology-open strategy, where a single vehicle platform can accommodate multiple propulsion systems, including battery-electric, plug-in hybrid, combustion, and hydrogen fuel cell variants.

By standardizing geometric and interface parameters across these systems, BMW enables shared production lines, reducing manufacturing complexity and supporting scalable deployment.

System-level performance and control integration
The hydrogen storage system operates as part of a combined powertrain that includes a fuel cell stack and a high-voltage battery. The vehicle also incorporates advanced drivetrain and chassis control software to manage energy distribution and dynamic performance.

The integration of storage, fuel cell, and control systems contributes to overall efficiency improvements compared to earlier fuel cell generations, particularly in energy management and power delivery.

Manufacturing strategy and scalability
The system is designed for integration into existing automotive production environments. By aligning storage dimensions and mounting interfaces with other drivetrain configurations, the platform supports mixed-model production on the same assembly line.

This approach enables cost optimization through shared tooling and processes, while maintaining flexibility to scale hydrogen vehicle production. The BMW Group plans broader deployment of hydrogen-powered models within its production network starting in 2028.

Position within hydrogen mobility development
Hydrogen fuel cell technology is positioned as a complementary solution within the wider electrification landscape, particularly for applications requiring long range and rapid refuelling.

The development of compact, structurally integrated storage systems addresses one of the key technical barriers to adoption. In this context, the presented architecture contributes to ongoing efforts to diversify propulsion technologies and reduce dependence on single energy infrastructures.

The project is supported under the Hy2Move initiative, part of the European IPCEI framework, with public funding from German federal and regional authorities to advance hydrogen mobility technologies.

Edited by an industrial journalist Sucithra Mani with AI assistance.

www.bmwgroup.com