In Situ TEM Investigation of ZnO Nanowires during Sodiation and Lithiation Cycling. Issue 9 (8th August 2017) - Asayesh‐Ardakani, Hasti
Abstract : The development of sodium‐ion batteries has drawn lots of attention recently due to the low‐cost and eco‐friendly sodium source. However, a fundamental understanding of the sodiation behavior for commonly used electrode materials is still limited. Here, combining in situ transmission electron microscopy, aberration‐corrected scanning transmission electron microscopy, and ex situ battery cycling tests, the lithiation and sodiation behavior of ZnO nanowires is investigated. The findings show a direct correlation between the mechanical behavior of the lithiated/sodiated ZnO nanowires and their electrochemical cyclability. The mechanical brittleness of LiZn and the formation of nanocracks lead to the poor cyclability of Li‐ion batteries with a ZnO anode. However, the sodiated ZnO nanowires show profuse dislocation plasticity. The observed high‐density dislocations offer the sodiated ZnO anode more ductility and subsequently better cyclability than its Li‐ion counterpart. The results reveal the importance of understanding the correlation between mechanical properties of battery electrodes and their cycling abilities. Abstract : The lithiation and sodiation of ZnO nanowires for sodium‐ion batteries are studied. The sodiated ZnO nanowires show better tolerance to external stresses than the lithiated ones. The ductility of the sodiation products offers the ZnO‐anode sodium‐ion battery better capacity retention during cycling.