Understanding of a Ni-Rich O3-Layered Cathode for Sodium-Ion Batteries: Synthesis Mechanism and Al-Gradient Doping.

O3-type NaNiMnCoO (NaNMC811) cathode active materials for sodium-ion batteries (SIBs), with a theoretical high specific capacity (∼ 187 mAh g), are in the preliminary exploration stage. This study comprehensively investigates NaNMC811 from multiple perspectives. For the first time, the phase evolution ( - - ) during the solid-state synthesis is systemically investigated, which elucidates in-depth the mechanisms of the thermal sodiation process.

Light-Sensitive Material Structure-Electrical Performance Relationship for Optical Memory Transistors Incorporating Photochromic Dihetarylethenes.

Photoswitchable organic field-effect transistors (OFETs) with embedded photochromic materials are considered as a promising platform for development of organic optical memory devices. Unfortunately, the operational mechanism of these devices and guidelines for selection of light-sensitive materials are still poorly explored. In the present work, a series of photochromic dihetarylethenes with a cyclopentenone bridge moiety were investigated as a dielectric/semiconductor interlayer in the structure of photoswitchable OFETs.

Biomimetic Approach to Inhibition of Photooxidation in Organic Solar Cells Using Beta-Carotene as an Additive.

Recent efficiency records of organic photovoltaics (OPV) highlight stability as a limiting weakness. Incorporation of stabilizers is a desirable approach for inhibiting degradation-it is inexpensive and readily up-scalable. However, to date, such additives have had limited success.

Metal-ion batteries meet supercapacitors: high capacity and high rate capability rechargeable batteries with organic cathodes and a Na/K alloy anode.

In this study, a dendrite-free liquid sodium-potassium alloy (NaK) anode with high capacity, a low reduction potential and fast kinetics was paired with two organic polymer cathodes, poly(N-phenyl-5,10-dihydrophenazine) (P1) and poly(hexaazatrinaphthylene) (P2), in metal-ion batteries. A high energy density of 631 W h kg-1 was achieved for one of the polymers (P1) at a discharge current density of 0.2 A g-1 (∼1C rate), while a still impressive specific energy of 443 W h kg-1 was achieved at 20 A g-1 (∼160C rate), which is an unprecedented value for post-lithium battery cathodes.

High-Energy and High-Power-Density Potassium Ion Batteries Using Dihydrophenazine-Based Polymer as Active Cathode Material.

Polymeric aromatic amines were shown to be very promising cathodes for lithium-ion batteries. Surprisingly, these materials are scarcely used for designing post-lithium batteries. In this Letter, we investigate the application of the high-voltage poly(-phenyl-5,10-dihydrophenazine) (p-DPPZ) cathodes for K-ion batteries.