Comparison of chronoamperometric response and rate-performance of porous insertion electrodes: Towards an accelerated rate capability test

The rate performance of secondary batteries is one of the key factors to push these technologies towards large-scale applications such as hybrid- and all-electric vehicles. Common test procedures, to evaluate the rate capability of novel active materials, electrodes, cells and complete batteries, provide indispensable information but are very time consuming. In the present study, a straightforward and timesaving experimental approach to determine the rate capability of porous insertion electrodes for Li-ion batteries is proposed. The chronoamperometric response of various electrodes with different active materials and design parameters is compared with conventional rate capability tests using a straightforward mathematical conversion approach. The experimental results clearly show that the rate performance can be deduced accurately from the chronoamperometric measurements. The theoretical evaluation of a straightforward equivalent circuit model also indicates an equivalence of the information contained in the conventional rate capability tests and the chronoamperometric response, which supports the experimental findings. The presented approach provides similar information compared to conventional rate capability tests with the benefits of being much more straightforward and significantly faster.