Modulating residual ammonium in MnO₂ for high-rate aqueous zinc-ion batteries

Abstract

Manganese dioxide (MnO2) as one of the promising cathode candidates has attracted great attention in aqueous zinc ion battery (ZIB). However, the undesirable dissolving of Mn2+ and the sluggish kinetic...

Cell Membrane-Coated Hollow Manganese Dioxide Drug Delivery Nanosystem for Targeted Liver Cancer Diagnosis and Treatment

“…XPS was used to assess the Mn valence state of CM–H-MnO 2 –SOR. According to the Mn 2p spectrum (Figure c), four deconvolution peaks were detected corresponding to Mn 4+ (655.1 and 643.5 eV) and Mn 3+ (653.6 and 642.3 eV) . The relative content of Mn 3+ and Mn 4+ are respectively 42.86% and 57.14%, agreeing with the features of low crystalline MnO 2 and the XRD results .…”

“…According to the Mn 2p spectrum (Figure 4c), four deconvolution peaks were detected corresponding to Mn 4+ (655.1 and 643.5 eV) and Mn 3+ (653.6 and 642.3 eV). 45 The relative content of Mn 3+ and Mn 4+ are respectively 42.86% and 57.14%, agreeing with the features of low crystalline MnO 2 and the XRD results. 46 Since the unstable Mn 3+ tends to convert to soluble Mn 2+ , the abundant Mn 3+ favors MnO 2 dissolution in vivo.…”

Regeneration of spent lithium manganate into cation‐doped and oxygen‐deficient MnO2 cathodes toward ultralong lifespan and wide‐temperature‐tolerant aqueous Zn‐ion batteries

“…Additionally, the elemental mapping images (Figure 2G) reveal the uniform distribution of C, N, O, and Mn elements on the carbon cloth in the LNMO d @CC composite, indicating the presence of doped nitrogen elements in these nanosheets 37,38 . The Li + /NH 4 + preintercalated manganese dioxide can not only expand the lattice spacing by the cation pre‐embedding strategy, thus providing enough defects and active sites for zinc ion storage, but also favor the electron density distribution 39 …”

“…37,38 The Li + /NH 4 + preintercalated manganese dioxide can not only expand the lattice spacing by the cation pre-embedding strategy, thus providing enough defects and active sites for zinc ion storage, but also favor the electron density distribution. 39 The X-ray diffraction (XRD) patterns of LNMO d @CC and MO@CC are depicted in Figure 3A, where the peaks located at about 18.1°, 25.7°, and 36.7°are related to the (200), (220), and (400) crystal planes of α-MnO 2 (JCPDS card No. 44-0141), respectively.…”

Yttrium-preintercalated layered manganese oxide as a durable cathode for aqueous zinc-ion batteries

“…10,11 Moreover, MnO 2 can form diverse crystal structures with versatile open frameworks, and atomic level modulations can be realized by means of foreign species doping, defect engineering, and so on. [12][13][14][15] The strategic design of electrolyte compositions such as Mn 2+ electrolyte additives and pH buffering allows Zn-MnO 2 batteries to exhibit improved cycle performance. 16,17 However, enabling MnO 2 to exhibit comparable electrochemical performance to the Zn anode still remains challenging.…”