Surface Restraint Synthesis of an Organic-Inorganic Hybrid Layer for Dendrite-Free Lithium Metal Anode.

Li metal is considered to be the most attractive anode for next-generation batteries because of its high specific capacity and low reduction potential. However, uncontrolled Li dendrite growth and low Coulombic efficiency cause severe capacity decay and safety issues. Here we propose a LiCl contained inorganic-organic hybrid layer on Li metal surface by a surface restraint dehalogenation reaction, which is highly uniform and features lithiophilic property as well as high ionic conductivity that can inhibit Li dendrite growth effectively. Consequently, the surface protected Li metal electrodes enable Li | Li symmetric cells to maintain a stable and low overpotential of 20 mV at a current density of 1 mA cm-2 after cycling over 3000 h, and enable Li | LiFePO4 pouch cell to decay only 0.05% in capacity per cycle at 5.0 C for 500 cycles, indicating excellent cycle stability and high rate capability. This work offers a simple and facile method to protect Li metal anode and promise a potential direction for industrialization of Li metal batteries.

Polymer Dehalogenation-Enabled Fast Fabrication of N,S-Codoped Carbon Materials for Superior Supercapacitor and Deionization Applications.

Doped carbon materials (DCM) with multiple heteroatoms hold broad interest in electrochemical catalysis and energy storage but require several steps to fabricate, which greatly hinder their practical applications. In this study, a facile strategy is developed to enable the fast fabrication of multiply doped carbon materials via room-temperature dehalogenation of polyvinyl dichloride (PVDC) promoted by KOH with the presence of different organic dopants. A N,S-codoped carbon material (NS-DCM) is demonstratively synthesized using two dopants (dimethylformamide for N doping and dimethyl sulfoxide for S doping). Afterward, the precursive room-temperature NS-DCM with intentionally overdosed KOH is submitted to inert annealing to obtain large specific surface area and high conductivity. Remarkably, NS-DCM annealed at 600 °C (named as 600-NS-DCM), with 3.0 atom % N and 2.4 atom % S, exhibits a very high specific capacitance of 427 F g-1 at 1.0 A g-1 in acidic electrolyte and also keeps ∼60% of capacitance at ultrahigh current density of 100.0 A g-1. Furthermore, capacitive deionization (CDI) measurements reveal that 600-NS-DCM possesses a large desalination capacity of 32.3 mg g-1 (40.0 mg L-1 NaCl) and very good cycling stability. Our strategy of fabricating multiply doped carbon materials can be potentially extended to the synthesis of carbon materials with various combinations of heteroatom doping for broad electrochemical applications.

[The study for the hemodynamics of expansive skin and the transplant time of skin flap designed by expansive skin].

OBJECTIVE: To study the change rule of the hemodynamics of expanded skins and research the transplant time of random-pattern flaps that are made of the expanded skin. METHODS: 72 ears of 64 rabbits were used as a subject of experiment. Four items of the contrasted skin (n = 8) and expanded skin (n = 8 x 8), Which include the microvessel diameter, the microvessel density, the blood velocity and the blood volume, were observed and measured by the microcirculatory imaging computer analysis system, the enzyme histochemical dyeing and the more functions colored pathological imaging computer analysis system. The length -width proportion and the largest area of the flaps that had made of the expansive skin and survived were measured. RESULTS: (1) The four items of expanded skin, that the microvessel diameter, the microvessel density, the blood velocity and the blood volume are 13.43 +/- 0.98 micrometer, 0.0472 +/- 0.0022, 1012.70 +/- 65.51 micrometer/s, 14.71 +/- 0.74 micrometer(3)/s respectively, are much bigger or quicker than those of contrasted skin [(7.22 +/- 0.71) micrometer, 0.0108 +/- 0.0002, (327.01 +/- 65.51) micrometer/s, (1.46 +/- 0.41) micrometer(3)/s] and there is the significant difference between both (6.49 < t < 49.49, P < 0.01). (2) The blood velocity increases in the expanding phases and always keeps on higher level. The other items all change periodically. Span of the period is four weeks. The microvessel diameter and the blood volume have a peak value at third weekend of every period and in the later period enhance more on the basis of the former period. The microvessel density changes in definite range in every period. (3) The surviving area of the random skin flaps is the largest which were made of the expanded skin in third weekend of every period, it changes more than those of other weekends in same period and later period is superior to the former period. There is a significant difference compared with contrasted random skin flaps (q = 3.7215, P < 0.05; q = 5.5026, P < 0.01). CONCLUSION: The hemodynamics of the expanded skin changes periodically in expansive course. The time of peak value of the blood volume is the best opportunity that random-pattern skin flaps are made of the expanded skin in every period.