Manganese-Based Tunnel-Type Cathode Materials for Secondary Li-Ion and K-Ion Batteries.

The rational design of novel cathode materials remains a key pursuit in the development of (post) Li-ion batteries. Considering the relative ionic and Stokes radii and open frameworks with large tunnels, Na-based compounds can act as versatile cathodes for monovalent Li-ion and post-Li-ion batteries. Here, tunnel-type sodium insertion material NaMnO is demonstrated as an intercalation host for Li-ion and K-ion batteries.

Iron-Based Mixed Phosphate NaFe(PO)PO Thin Films for Sodium-Ion Microbatteries.

Iron-based polyanionic materials can be exploited to realize low cost, durable, and safe cathodes for both bulk and thin film sodium-ion batteries. Herein, we report pulsed laser deposited mixed phosphate NaFe(PO)PO as a positive electrode for thin film sodium-ion microbatteries. The bulk material and thin films of NaFe(PO)PO are employed by solution combustion synthesis (SCS) and the pulsed laser deposition (PLD) technique, respectively.

Cobalt and Nickel Phosphates as Multifunctional Air-Cathodes for Rechargeable Hybrid Sodium-Air Battery Applications.

Noble-metal-free bifunctional electrocatalysts are indispensable to realize low-cost and energy-efficient rechargeable metal-air batteries. In addition, power density, energy density, and cycle life of these metal-air batteries can be improved further by utilizing the fast faradaic reactions of metal ions in the catalyst layer together with the oxygen evolution/reduction reactions (OER/ORR) for charge storage. In this work, we propose mixed metal phosphates of nickel and cobalt, NiCo(PO) ( = 0,1, 1.

Highly Electroactive Ni Pyrophosphate/Pt Catalyst toward Hydrogen Evolution Reaction.

Robust electrocatalysts toward the resourceful and sustainable generation of hydrogen by splitting of water via electrocatalytic hydrogen evolution reaction (HER) are a prerequisite to realize high-efficiency energy research. Highly electroactive catalysts for hydrogen production with ultralow loading of platinum (Pt) have been under exhaustive exploration to make them cutting-edge and cost-effectively reasonable for water splitting. Herein, we report the synthesis of hierarchically structured nickel pyrophosphate (β-NiPO) by a precipitation method and nickel phosphate (Ni(PO)) by two different synthetic routes, namely, simple cost-effective precipitation and solution combustion processes.

Electrochemical potassium-ion intercalation in NaCoO: a novel cathode material for potassium-ion batteries.

Reversible electrochemical potassium-ion intercalation in P2-type NaCoO was examined for the first time. Hexagonal NaCoO platelets prepared by a solution combustion synthesis technique were found to work as an efficient host for K intercalation. They deliver a high reversible capacity of 82 mA h g, good rate capability and excellent cycling performance up to 50 cycles.

A Metal-Organic Framework Derived Porous Cobalt Manganese Oxide Bifunctional Electrocatalyst for Hybrid Na-Air/Seawater Batteries.

Spinel-structured transition metal oxides are promising non-precious-metal electrocatalysts for oxygen electrocatalysis in rechargeable metal-air batteries. We applied porous cobalt manganese oxide (CMO) nanocubes as the cathode electrocatalyst in rechargeable seawater batteries, which are a hybrid-type Na-air battery with an open-structured cathode and a seawater catholyte. The porous CMO nanocubes were synthesized by the pyrolysis of a Prussian blue analogue, Mn[Co(CN)]·nHO, during air-annealing, which generated numerous pores between the final spinel-type CMO nanoparticles.

Hydrothermal synthesis and electrochemical performances of 1.7 V NiMoO₄⋅xH₂O||FeMoO₄ aqueous hybrid supercapacitor.

One-dimensional (1D) NiMoO4⋅xH2O nanorods and β-FeMoO4 microrods are successfully synthesized by simple hydrothermal method without using any organic solvents. X-ray diffraction (XRD) patterns reveal the single phase formation of nickel molybdate (NiMoO4⋅xH2O) and pure monoclinic phase of β-FeMoO4. The growth of one dimensional morphology of both the molybdates are identified from scanning and transmission electron microscopes (SEM and TEM).