Regenerable Cu-intercalated MnO2 layered cathode for highly cyclable energy dense batteries

Abstract

Manganese dioxide cathodes are inexpensive and have high theoretical capacity (based on two electrons) of 617 mAh g−1, making them attractive for low-cost, energy-dense batteries. They are used in non-rechargeable batteries with anodes like zinc. Only ∼10% of the theoretical capacity is currently accessible in rechargeable alkaline systems. Attempts to access the full capacity using additives have been unsuccessful. We report a class of Bi-birnessite (a layered manganese oxide polymorph mixed with bismuth oxide (Bi2O3)) cathodes intercalated with Cu2+ that deliver near-full two-electron capacity reversibly for >6,000 cycles. The key to rechargeability lies in exploiting the redox potentials of Cu to reversibly intercalate into the Bi-birnessite-layered structure during its dissolution and precipitation process for stabilizing and enhancing its charge transfer characteristics. This process holds promise for other applications like catalysis and intercalation of metal ions into layered structures. A large prismatic rechargeable Zn-birnessite cell delivering ∼140 Wh l−1 is shown.

Novel Insights into Energy Storage Mechanism of Aqueous Rechargeable Zn/MnO2 Batteries with Participation of Mn2+

“…In fact, for the active materials in aqueous ZIBs and some other rechargeable aqueous batteries, their structure and phase generally undergo complex changes during charge/discharge processes (e.g., the active materials can interact with not only metal ions, but also H + , OH − , and water molecules) [39]. This is an important reason why the energy storage mechanism of MnO 2 cathode in ZIBs is still inconclusive [40][41][42][43].…”

Joint Charge Storage for High‐Rate Aqueous Zinc–Manganese Dioxide Batteries

“…Layered δ‐MnO 2 was synthesized for rechargeable aqueous Zn batteries using simple hydrothermal method according to previous report . The crystal structure of δ‐MnO 2 is made of loosely bound layers of edge‐shared MnO 6 located on the (001) plane (Figure ).…”

Impact of Triethanolamine as an Additive for Rechargeable Alkaline Zn/MnO2Batteries under Limited Depth of Discharge Conditions

“…− cycling, 0.1 C rate) in addition to noting synergistic effects when combining these additives. 27 Overall, with the exception of the work of Yadav et al, 16 stabilization of the MnO 2 cathode has been observed but mainly at non-practical low mass loadings (< 50%) and/or with thin electrodes (< 100 μm thick). Zn anode additives intended to reduce hydrogen evolution, mitigate shape change, suppress dendrite formation, and slow Zn transport have also been reported in the literature including In, 36 Bi, 36 Pb, 36 carboxymethyl cellulose, 37 tartaric acid, 38 polyethylene glycol (PEG), 38 Ca(OH) 2 , 6,39 tetra-alkyl ammonium hydroxides, 40 and sodium dodecylbenzene sulfonate (SDBS).…”

“…These Bi and Cu stabilized MnO 2 cathodes have delivered the highest areal capacities for MnO 2 electrodes to date (∼29 mAh cm −2 , 60 wt% loading, 0.046 cm thick). 16 While a remarkable achievement, the MnO 2 electrodes are still susceptible to Zn poisoning (irreversibly forming ZnMn 2 O 4 ) and also required initial cycling versus a Ni(OH) 2 counter electrode in order to "form" the electrodes before they could be paired with a Zn anode to form the Zn/MnO 2 battery. 16,17 Comparatively, >900 cycles were achieved when a modified MnO 2 electrode was cycled against a Zn anode under relatively high Zn utilization conditions (∼15% DOD on Zn).…”

“…16 While a remarkable achievement, the MnO 2 electrodes are still susceptible to Zn poisoning (irreversibly forming ZnMn 2 O 4 ) and also required initial cycling versus a Ni(OH) 2 counter electrode in order to "form" the electrodes before they could be paired with a Zn anode to form the Zn/MnO 2 battery. 16,17 Comparatively, >900 cycles were achieved when a modified MnO 2 electrode was cycled against a Zn anode under relatively high Zn utilization conditions (∼15% DOD on Zn). 17 This was achieved by employing a Ca(OH) 2 membrane as a separator which has been demonstrated to sequester Zn and prevent its transport to the cathode.…”