Efficient cell design and fabrication of concentration‐gradient composite electrodes for high‐power and high‐energy‐density all‐solid‐state batteries

All‐solid‐state batteries are promising energy storage devices in which high‐energy‐density and superior safety can be obtained by efficient cell design and the use of nonflammable solid electrolytes, respectively. This paper presents a systematic study of experimental factors that affect the electrochemical performance of all‐solid‐state batteries. The morphological changes in composite electrodes fabricated using different mixing speeds are carefully observed, and the corresponding electrochemical performances are evaluated in symmetric cell and half‐cell configurations. We also investigate the effect of the composite electrode thickness at different charge/discharge rates for the realization of all‐solid‐state batteries with high‐energy‐density. The results of this investigation confirm a consistent relationship between the cell capacity and the ionic resistance within the composite electrodes. Finally, a concentration‐gradient composite electrode design is presented for enhanced power density in thick composite electrodes; it provides a promising route to improving the cell performance simply by composite electrode design.