Alkaline batteries using zinc electrodes are attractive to be used in large-scale energy storage systems owing to their low cost, high safety standards and high energy density. On the other hand, the zinc electrodes suffer from shape change to lead to capacity decrease. Such shape change has been clarified by the combination of operand x-ray diffraction and operando optical microscopy to find that inhomogeneous current distribution promotes zinc deposition at the edge and the resultant loss of zinc oxide [1]. This study shows whether the reported rechargeability enhancement by the hydrophilic-polymer additives [2] can be ascribed to the mitigation of the reaction inhomogeneity. In this study, we used butendiol vinyl alcohol co-polymer (BVOH) as the additive to enhance the turnover number of zinc (total cycled capacity divided by the installed zinc capacity). The operando x-ray diffraction revealed that ZnO was mostly lost after the 2 nd cycle at the edge of the electrode without BVOH, while broad diffraction of ZnO was captured with BVOH. The operando optical analysis showed that course uneven Zn deposition was formed at the vicinity of the current collectors without BVOH, whereas fine homogeneous Zn deposition was observed with BVOH, suggesting ZnO fixation during the oxidation process. It is deduced that the higher the BVOH concentration is, the more viscose the electrolyte becomes to inhibit zincate diffusion, to enhance ZnO fixation, and to improve the rechargeability. [Acknowledgment] This work is based on results obtained from a project, JPNP21006, commissioned by the New Energy and Industrial Technology Development Organization (NEDO). [References] [1] A. Ikezawa et al., J. Power Sources , 507 , 230291 (2021). [2] T. Kakeya et al., J. Power Sources , 407 , 180 (2018). Figure 1