An apparatus is configured to monitor a plurality of layers of a battery layer stack during manufacturing. The apparatus includes at least one X-ray source configured to generate X-rays with X-ray energies that exhibit contrast of transmission through the plurality of layers of the battery layer stack. The at least one X-ray source is configured to face a first side of the battery layer stack. The apparatus further includes at least one sensor configured to detect the X-rays transmitted through the plurality of layers. The at least one sensor is configured to face a second side of the battery layer stack.