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The insulation of sulfur and Li2S/Li2S2 (discharge products) and the “shuttle” of soluble lithium polysulfides (LiPSs) seriously limit the research of high specific capacity lithium-sulfur (Li-S) batteries with high sulfur loading. Inspired by the natural architecture of pomelo peels, we report a self-supporting carbon framework (SCF) modified by reduced graphene oxide (rGO) as conductive skeleton and sulfur carrier for the cathode of rechargeable Li-S batteries. The high initial capacity (1489.65 mA h g−1) of SCF@rGO/S binder-free cathode with the high sulfur areal loading (∼5.50 mg cm−2) arise from the improved batteries conductivity by the interconnecting conductive skeleton. The SCF@rGO with hierarchical porous structure, abundant microchannels and oxygenic functional groups can effectively physical limit/intercept and chemical adsorption/anchor LiPSs, thereby improving the utilization of active sulfur and promoting the reuse. Sufficient active sites in SCF@rGO/S provide close electrical contact to accelerate electrons and ions transfer, resulting in high electrochemical activity and redox kinetics. Consequently, the SCF@rGO/S cathode exhibits an outstanding capacity retention (569.66 mA h g−1) and cycle stability at 1 C for over 200 long-term cycles with a decline of only 0.13% per cycle. Even at 2 C, the capacity is still up to 645.59 mA h g−1. The SCF@rGO/S cathode provide a feasible approach and strategy to develop high performance Li-S batteries.

Abstract Layered Li-rich oxides (LLROs) have been considered as promising cathodes for next-generation Li-ion batteries due to their low cost and high reversible capacity. However, drawbacks such as voltage decay and poor cycle & rate performance hinder their commercialization. These problems are mainly related to the interface reaction and herein we fabricate nanostructured ionic and electronic bicontinuous pathways for Li 1.2 Mn 0.6 Ni 0.2 O 2 simultaneously by modifying the cyclized-polyacrylonitrile (c-PAN) on the surface. This unique design constructs spinel structure on the surface of layered materials as the 3D pathway for Li-ions and conductive framework for electrons to transfer from the current collector through the acetylene black to the surface of every single particle as well, therefore providing both ionic and electronic pathways. Electrochemical tests shows that the cycle & rate performances of the material are significantly improved. After 80 cycles at 0.1C (1C = 250 mA g−1), the capacity retention reaches 97.7%. The results identify that the conductive modification is conducive to maintain the capacity from the spinel phase and control the amorphization of the material, thereby helping to get remarkable cycle performance. We also propose the mechanism of spinel phase formation. This bicontinuous pathways design opens up significant opportunities for the novel design of lithium-rich oxides. Graphical abstract Image 1 Highlights • Ionic and electronic pathways were fabricated outside the Li 1.2 Mn 0.6 Ni 0.2 O 2 (LMNO). • LMNO with bicontinuous pathways shows improved cycling and rate performances. • The formation mechanism of the ionic and electronic pathways are discussed. [ABSTRACT FROM AUTHOR]

We prepared a novel amperometric sensor based on nickel cobalt layered double hydroxide (NiCo‐LDH) coupling with ultrathin polypyrrole shell (LDH@PPy) for enzyme‐free determination of glucose. Using a simple vapor polymerization route, PPy forms an internal conductive framework surrounding the LDH lamellas, leading to improved electronic conductivity as well as mitigated electrochemical impedance. As a consequence, the LDH@PPy sensor endows excellent electrocatalytic performance for glucose determination. High sensitivity (46.04 μA mM−1 cm−2 and 292.84 μA mM−1 cm−2), wide linear range (5–50 μM and 0.05–8.2 mM), and a low detection limit of 0.80 μM (S/N=3) could be implemented. The optimization of operation potential, reproducibility, and anti‐interference properties of the sensor were also conducted. The LDH@PPy composite presents a promising candidate for rapid and accurate determination of glucose in practical applications. [ABSTRACT FROM AUTHOR]

Abstract: Open-ended α-Ni(OH)2 nanotubes grown on three-dimensional (3D) Ni framework were prepared by hydrolysis of nickel chloride in the presence of hexagonal ZnO nanorods. The urea electrolysis was investigated by voltammetry and chronoamperometry in 1M KOH electrolyte. Macroporous conductive Ni substrate provided fast ion, gas, and electron transport within the electrode. The open-ended nanotubes resulted in an increase in the effective surface area, and therefore more active sites were exposed to electrolyte for urea electrolysis. 3D Ni framework with attached Ni(OH)2 nanotube arrays exhibited a much higher current density than that with attached Ni(OH)2 film during urea electrolysis. [Copyright &y& Elsevier]

Because of the disadvantages of commercial graphite anodes for high-power lithium-ion batteries, a kind of spinel nanolithium titanate (Li 4 Ti 5 O 12 )/graphene microsphere composite [denoted as LTO/reduced graphene oxide (rGO)] is successfully synthesized. The as-prepared composite is made up of curled graphene sheets which are anchored with nano-Li 4 Ti 5 O 12 particles. These nano-Li 4 Ti 5 O 12 particles are uniformly decorated on the conductive graphene framework and their sizes range from just 15 to 20 nm. In the as-prepared composite, the curled graphene sheets form a unique mesopore-oriented structure which provides plenty of three-dimensional channels for ion transportation. These structure characters greatly improve both the electron conductivity and Li + diffusion ability. The ratio of pseudocapacitive capacity dramatically increases in the obtained LTO/rGO composite and generates excellent ultrahigh rate performances. The as-prepared LTO/rGO composite delivers a reversible capacity of 70.3 mA h g -1 at 200 C and a capacity retention of 84.7% after 1000 cycles at 50 C. As the current density varies from 30 to 100 C, the special capacity remains unchanged (about 112 mA h g -1 ). These results show that the graphene framework-supported nano-Li 4 Ti 5 O 12 composite has potential application in high-power lithium-ion batteries.