Evolution of the porous structure for phosphoric acid etching carbon as cathodes in Li–O_(2) batteries:Pyrolysis temperature-induced characteristics changes

Although biomass-derived carbon(biochar)has been widely used in the energy field,the relation between the carbonization condition and the physical/chemical property of the product remains elusive.Here,we revealed the carbonization condition's effect on the morphology,surface property,and electrochemical performance of the obtained carbon.An open slit pore structure with shower-puff-like nanoparticles can be obtained by finely tuning the carbonization temperature,and its unique pore structure and surface properties enable the Li–O_(2) battery with cycling longevity(221 cycles with 99.8%Coulombic efficiency at 0.2 mA cm^(−2) and controlled discharge–charge depths of 500 mAh g^(−1))and high capacity(16,334 mAh g^(−1) at 0.02 mA cm^(−2)).This work provides a greater understanding of the mechanism of the biochar carbonization procedure under various pyrolysis conditions,paving the way for future study of energy storage devices.

Achieving a superior Na storage performance of Fe-based Prussian blue cathode by coating perylene tetracarboxylic dianhydride amine

Fe-based Prussian blue(Fe-PB)cathode material shows great application potential in sodium(Na)-ion batteries due to its high theoretical capacity,long cycle life,low cost,and simple preparation process.However,the crystalline water and vacancies of Fe-PB lattice,the low electrical conductivity,and the dissolution of metal ions lead to limited capacity and poor cycling stability.In this work,a perylene tetracarboxylic dianhydride amine(PTCDA)coating layer is successfully fabricated on the surface of Fe-PB by a liquid-phase method.The aminated PTCDA(PTCA)coating not only increases the specific surface area and electronic conductivity but also effectively reduces the crystalline water and vacancies,which avoids the erosion of Fe-PB by electrolyte.Consequently,the PTCA layer reduces the charge transfer resistance,enhances the Na-ion diffusion coefficient,and improves the structure stability.The PTCA-coated Fe-PB exhibits superior Na storage performance with a first discharge capacity of 145.2 mAh g^(−1) at 100 mA g^(−1).Long cycling tests exhibit minimal capacity decay of 0.027%per cycle over 1000 cycles at 1 A g^(−1).Therefore,this PTCA coating strategy has shown promising competence in enhancing the electrochemical performance of Fe-PB,which can potentially serve as a universal electrode coating strategy for Na-ion batteries.

The electrolyte comprising more robust water and superhalides transforms Zn-metal anode reversibly and dendrite-free

A great challenge for all aqueous batteries,including Zn-metal batteries,is the parasitic hydrogen evolution reaction on the low-potential anode.Herein,we report the formula of a highly concentrated aqueous electrolyte that mitigates hydrogen evolution by transforming water molecules more inert.The electrolyte comprises primarily ZnCl_(2) and LiCl as an additive,both of which are inexpensive salts.The O-H covalent bonds in water get strengthened in a chemical environment that has fewer hydrogen bonding interactions and a greater number of Zn-Cl superhalides,as suggested by integrated characterization and simulation.As a result,the average Coulombic efficiency of zincmetal anode is raised to an unprecedented>99.7%at 1mA cm^(−2).In the new electrolyte,the plating/stripping processes leave the zinc-metal anode dendrite-free,and the zinc-metal anode delivers stable plating/stripping cycles for 4000 hours with an areal capacity of 4 mAh cm^(−2) at 2mA cm^(−2).Furthermore,the high Coulombic efficiency of zinc-metal anode in the ZnCl_(2)-LiCl mixture electrolyte is demonstrated in full cells with a limited anode.The V_(2)O_(5)·H_(2)O||Zn full cell with an N/P mass ratio of 1.2 delivers a stable life of more than 2500 cycles,and the LiMn_(2)O_(4)||Zn hybrid cell with an N/P mass ratio of 0.6 exhibits 1500 cycles in its stable life.

新中国行政复议发展历程

01制度初创我国行政复议制度肇始于新中国成立之初,分散规定于有关单行法,并探索开展办案实践,为我国开启行政复议的统一立法之路夯实了制度基础、积累了宝贵的实践经验。1950年10月颁布的《中央人民政府财政部设置财政检查机构办法》第6条规定:"被检查部门,对检查机构之措施,认为不当时,得备具理由,向其上级检查机构,声请复核处理。"这一条文所规定的"复核处理",即为新中国成立后最早有记载的行政复议制度。

Prussian Blue Analogues as Electrodes for Aqueous Monovalent Ion Batteries

Aqueous batteries have engendered increasing attention as promising solutions for stationary energy storage due to their potentially low cost and innate safety.In various aqueous battery systems,Prussian blue analogues(PBAs)represent a class of promising electrode materials with fascinating electrochemical performance,owing to their large open frameworks,abundant ion insertion sites,and facile preparation.To date,PBAs have shown substantial progress towards storage of alkali metal ions(Li^(+),Na^(+),and K^(+)),H^(+),and NH4^(+) in aqueous electrolytes,which,however,has yet not been specifically summarized.This review selects some representative research to introduce the progress of PBAs in these battery systems and aims to discuss the crucial role of ionic charge carrier in affecting the overall electrode performance.Besides,some critical knowledge gaps and challenges of PBA materials have been pointed out for future development.

Uniformly dispersed FeOx atomic clusters by pulsed arc plasma deposition： An efficient electrocatalyst for improving the performance of Li-O2 battery

The present study explored a new method to improve the catalytic activity of non-precious metals, especially in electrochemical reactions. Highly ionized Fe plasma produced by arc discharge was uniformly deposited on a porous carbon substrate and formed atomic clusters on the carbon surface. The as-prepared FeO~/C material was tested as a cathode material in a rechargeable Li-02 battery under different current rates. The results showed significant improvement in battery performance in terms of both cycle life and reaction rate. Furthermore, X-ray diffraction （XRD） and scanning electron microscopy （SEM） results showed that the as-prepared cathode material stabilized the cathode and reduced side reactions and that the current rate was a critical factor in the nucleation of the discharge products.