Tailoring of a visible-light-absorbing biaxial ferroelectric towards broadband self-driven photodetection

2D lead-iodide ferroelectrics usually possess a wide bandgap along with the lacking of ferroelectric bulk photovoltaic effects due to the monolayered inorganic perovskite sheets. Here, the authors present a pathway to increase the thickness of inorganic sheets while retaining ferroelectricity

Co/carbon nanofiber with adjustable size and content of Co nanoparticles for tunable microwave absorption and thermal conductivity

Electromagnetic pollution and heat dissipation problems are becoming increasingly worthy of attention due to the rapid development of electronic devices, which puts forward an urgent demand for microwave absorbers with excellent thermal management performance. Herein, high-performance Co/carbon nanofiber (Co/CNF) microwave absorbers with high thermal conductivity were fabricated by facile step-by-step method. The microwave absorption properties can be readily tuned by adjusting the content and size of Co nanoparticles through concentration gradient adsorption. Benefiting from the formation of dielectric and magnetic coupling network, Co/CNF composites possess intensive dipole polarization, interface polarization, and magnetic loss. The optimal Co/CNF composites exhibit outstanding microwave absorption performance with a minimum reflection loss (RL) of −53.0 dB at 11.44 GHz, and a maximum effective absorption bandwidth (EAB) of 5.5 GHz. In addition, the thermal conductivities of the Co/CNF-natural rubber (Co/CNF-NR) composites are significantly improved. This work may inspire the exploration of high-efficiency heat-conduction microwave absorbers based on CNF

Tuning Li-enrichment in high-Ni layered oxide cathodes to optimize electrochemical performance for Li-ion battery

To understand what and how structural properties affect battery performance, and to optimize the structural properties accordingly are of crucial importance to improve the performance of cathode materials for advanced Li-ion batteries. Herein, we investigated the influence of Li-enrichment in Li1+x(Ni0.8Co0.2)1-xO2 transition metal (TM) oxide cathodes, obtained by sintering Ni0.8Co0.2(OH)2 precursor with different amount of Li sources. Compared with stoichiometric Li1+x(Ni0.8Co0.2)1-xO2 (i.e. x = 0, Li:TM = 1:1), the improvements of cycling stability and rate performance were observed in material with moderate degree of Li-enrichment with respect to TMs (i.e. x = 0.019, Li:TM = 1.04:1). Further increase in Li:TM ratio up to 1.07 diminishes the electrochemical performance. Multi-scale structural characterizations including neutron diffraction and aberration-corrected transmission electron microscopy measurements show that the Li-enrichment leads to a monotonical increase in both Li/Ni exchange ratio and Li slab space. Based on the results, we argue that, in material with moderate Li-enrichment, larger Li slab space can facilitate the diffusion of Li ions and a certain amount of Li/Ni disordering can also mitigate the contraction of layered structure, therefore resulting in an optimized electrochemical performance; while in material with excessive Li:TM ratio, the diffusion path can be partially blocked due to the presence of redundant Ni ions in Li layers

Cooling Induced Surface Reconstruction during Synthesis of High-Ni Layered Oxides

Cooling Induced Surface Reconstruction during Synthesis of High-Ni Layered Oxide