Characterization of Advanced Positive Electrode Materials for Li-Ion Batteries

The demand for electric vehicles equipped with Li-ion batteries is growing to develop low carbon society. Ni-enriched layered materials are used as electrode materials of Li-ion batteries for electric vehicle applications. However, available reversible capacity of Ni-enriched layered materials is approaching its theoretical limit. Therefore, innovation and development of new positive electrode materials are necessary. Recently, many cation-disordered rocksalt oxides have been proposed as a new series of electrode materials. Nevertheless, insufficient electrode kinetics for the cation-disordered rocksalt system limits its use for practical applications. One simple strategy is synthesizing nanosized materials to overcome a problem of electrode kinetics (for electrons, holes and ions), and electrode kinetics are significantly improved through nanosizing.^1-4) Structural disordering also triggers unique electrode properties associated with different local environments for cations/anions.^4-7) From these results, we discuss the advantage and uniqueness of nanostructured cation-disordered rocksalt materials for high-energy advanced Li-ion batteries.<br/><br/><b>References </b><br/>1) Y. Kobayashi et al., and N. Yabuuchi, <i>Materials Today</i>, <b>37</b>, 43 (2020).<br/>2) M. Sawamura et al., and N. Yabuuchi, <i>ACS Central Science</i>, <b>6</b>, 2326 (2020).<br/>3) J. Yun et al., and N. Yabuuchi, <i>PNAS</i>, <b>118</b>, e202496911 (2021).<br/>4) N. Yabuuchi, <i>Current Opinion in Electrochemistry</i>, <b>34</b>, 100978 (2022).<br/>5) R. Fukuma et al., and N. Yabuuchi, <i>ACS Central Science</i>, <b>8</b>, 775 (2022).<br/>6) I. Konuma et al., and N. Yabuuchi, <i>Nature Materials</i>, <b>22</b>, 225 (2023).<br/>7) A. Kanno et al., and N. Yabuuchi, <i>ACS Energy Letters</i>, <b>8</b>, 2753−2761 (2023).