δ‐MnO₂ Nanofibers: A Promising Cathode Material for New Aluminum‐Ion Batteries

Abstract

δ-MnO 2 nanofibers, synthesized by using a simple, low-cost solgel method, showed high electrochemical performance as a cathode for rechargeable Al-ion batteries (AIBs). δ-MnO 2 presented an initial discharge capacity of 59 mA h g À 1 and stabilized at 37 mA h g À 1 at a current rate of 100 mA g À 1 after 15 cycles and for more than 100 cycles with almost a 99 % coulombic efficiency. Different plateaus in charge/discharge curves, consistent with CV peaks, revealed the Al-ion insertion/ deinsertion and the electrochemical stability of the battery. Moreover, different rate CV measurements revealed the pseudocapacitive behavior of δ-MnO 2 in AIBs. The obtained charge/discharge capacities are ten times higher than previous studies performed with this material. Ex situ Raman and highresolution TEM measurements in different charge/discharge states revealed structural information of δ-MnO 2 upon Al-ion intercalation/deintercalation.

Oxygen defect engineering endows Co3O4 nanosheets with advanced aluminum ion storage

“…16,44–46 These results are competitive among the reported oxide cathodes for AIBs shown in Fig. 4h and Table S1,† 23,47–55 strongly supporting the intriguing structural superiorities of Co 3 O 4− x porous nanosheets as an advanced cathode for AIBs. The corresponding Ragone plot in Fig.…”

“…4i shows that Co 3 O 4− x can deliver a high energy density of 292.1 W h kg −1 (based on the cathode mass) and power density of 1000 W kg −1 , which are superior or comparable to those of previously reported oxide-based AIB cathodes. 23,47–54 In addition, to demonstrate the practical application potential of the Co 3 O 4− x /Al battery, both our fabricated Co 3 O 4− x /Al batteries were connected in series, which could easily light up 28 light emitting diode (LED) lamps (Fig. 4j), and the voltage of the batteries in series could reach 3.63 V (Fig.…”

Stable Manganese‐Oxide Composites as Cathodes for Zn‐Ion Batteries: Interface Activation from In Situ Layer Electrochemical Deposition under 2 V

“…Subsequently, the sample was filtered and dried in a stove at 80 °C for 12 h. Following a thermal treatment of 400 °C for 4 h. was carried out. [ 17 ] This sample is hereinafter referred to as KMn.…”

“…[15] Therefore, different functional composites can be synthesized from manganese salts (both Mn(II) salts and oxo-composites in which Mn is in a higher oxidation state) with carboxylic acids or with alcohols. [16,17] Interestingly, the obtained products will presumably present different morphologies, which could facilitate the ions' diffusion in the intercalation processes. In this context, we were interested in the study of aqueous zincion batteries with different manganese oxides cathodes.…”

A first-principles investigation of α, β, and γ-MnO2 as potential cathode materials in Al-ion batteries

“…In the context of AIB, each polymorph have been investigated experimentally. [23][24][25][26][27] Theoretically, a-MnO 2 has been systematically researched. Each phase was investigated with ions commonly used in batteries intercalated within.…”