Crystal structure-dependent ammonium-ion storage mechanisms in nanostructured MnO2 polymorphs - Jingang Wu; Binbin Wei; Quanxing Guo; Haojun Zeng; Xin Liu; Qiaoyan Chen; Xutao Yan; Yuechan Li; Qi-Yuan Fan; Zhengbing Qi; Hanfeng Liang (Chemical Engineering Journal, 2025)