Influence of current tabs on performance and aging of multi-tab 26650-type LFP lithium-ion batteries

Two high-power lithium-ion batteries of 26650-type adopting LiFePO₄|C cell chemistry are non-invasively characterized using electrochemical, thermodynamical, and diffraction-based methods. Their discharging and charging behavior are probed using incremental capacity analysis and differential voltage analysis normalized to the state-of-charge. Differential thermal analysis allows for a qualitative probe of the electrolyte subsystem in both cells. Diffraction-based non-destructive characterization using both synchrotron and neutron radiation (in the form of X-ray diffraction computed tomography and spatially-resolved neutron diffraction) reveals the state-of-lithiation for cathode and anode materials in the fully-charged state at operando conditions. Electrochemical characteristics, influence of cell geometry, and state-of-lithiation are compared and discussed, and their effect and interplay are elucidated in detail.