The battery system defines the experience of driving electric vehicles more than any other element. The energy density of the cells defines power to weight ratio and driving range, and the time required for charging needs to align with customer expectations. The battery pack is often the most expensive component in a new energy vehicle. Raw materials dominate the cost of battery cells, which is why designing a new energy vehicle requires balancing performance against material costs without compromising safety.
ZEISS Industrial Microscopy Series give battery engineers and materials scientists the insights needed to overcome these challenges.
Designing new energy vehicles for performance and cost begins with battery technology. Developing new active materials for the cathode, anode and separator is key to improve the capacity, charging behaviour and lifetime while controlling costs. For graphite anode materials, porosity and facile preparation are key to determine discharging behaviour. While adding silicon to the anode can increase energy density, it is necessary to monitor and control lifetime issues. Electron and X-ray microscopy solutions from ZEISS provide the necessary imaging and analytical capabilities to determine the relevant material properties – critical for further advancing battery performance and safety.
Controlling the quality of incoming goods is critical to ensure uniformity and consistency in the supply of materials. Key issues in supply chain control range from the qualification of raw material powders, and the quality control of the aluminium, copper and separator foils. Light and confocal microscopes from ZEISS can examine the surface roughness and microstructure of foils. Electron microscopes control the elemental composition, particle size distributions and/or particle contamination in raw material powders. Complete batteries can be investigated using X-ray microscopy to ensure a uniform supply.
The performance of batteries changes over their lifetime, and it’s critical to understand these longitudinal aging effects. Under a microscope, one can observe that charging and discharging creates chemical and structural changes that alter the electrode materials. Repeated swelling and contracting of the battery leads to crack propagation, void evolution, loss of mechanical stability and electrical connectivity, and thus capacity fading or failure of the cell. ZEISS electron microscopy allows for microscale electrical property mapping, which makes it possible to create a “conductivity map” of the active battery materials.