Porous metal oxides in the role of electrochemical CO_(2) reduction reaction

The global energy-related CO_(2) emissions have rapidly increased as the world economy heavily relied on fossil fuels.This paper explores the pressing challenge of CO_(2) emissions and highlights the role of porous metal oxide materials in the electrocatalytic reduction of CO_(2)(CO_(2)RR).The focus is on the development of robust and selective catalysts,particularly metal and metal-oxide-based materials.Porous metal oxides offer high surface area,enhancing the accessibility to active sites and improving reaction kinetics.The tunability of these materials allows for tailored catalytic behavior,targeting optimized reaction mechanisms for CO_(2)RR.The work also discusses the various synthesis strategies and identifies key structural and compositional features,addressing challenges like high overpotential,poor selectivity,and low stability.Based on these insights,we suggest avenues for future research on porous metal oxide materials for electrochemical CO_(2) reduction.

Simultaneous realization of high sulfur utilization and lithium dendrite-free via dual-effect kinetic regulation strategy toward lithium-sulfur batteries

With the high theoretical specific capacity and energy density,lithium-sulfur batteries(LSBs)have been intensively studied as promising candidates for energy storage devices.However,LSBs are largely hindered by inferior sulfur utilization and uncontrollable dendritic growth.Herein,a hierarchical functionalization strategy of stepwise catalytic-adsorption-conversion for sulfur species via the synergetic of the efficiently catalytic host cathode and light multifunctional interlayer has been proposed to concurrently address the issues arising on the dual sides of the LSBs.The multi-layer SnS_(2) micro-flowers embedded into the natural three-dimensional(3D)interconnected carbonized bacterial cellulose(CBC)nanofibers are fabricated as the sulfur host that provides numerous catalytic sites for the rapid catalytic conversion of sulfur species.Moreover,the distinctive CBC-based SnO_(2)-SnS_(2) heterostructure network accompanied high conductive carbon nanofibers as the multifunctional interlayer promotes the rapid anchoringdiffusion-conversion of lithium polysulfides,Li^(+)flux redistribution,and uniform Li deposition.LSBs equipped with our strategy exhibit a high reversible capacity of 1361.5 m A h g^(-1)at 0.2 C and superior cycling stability with an ultra-low capacity fading of 0.031%per cycle in 1000 cycles at 1.5 C and 0.046%at 3 C.A favorable specific capacity of 859.5 m A h g^(-1)at 0.3 C is achieved with a high sulfur mass loading of 5.2 mg cm^(-2),highlighting the potential of practical application.The rational design in this work can provide a feasible solution for high-performance LSBs and promote the development of advanced energy storage devices.

Recent progress in rate and cycling performance modifications of vanadium oxides cathode for lithium-ion batteries

The emergency of high-power electrical appliances has put forward higher requirements for the power density of lithium-ion batteries.Vanadium oxides with large theoretical capacities and high operating voltages are considered as prospective alternatives for the cathode of a new generation of lithium-ion batteries.However,the poor rate and cycling performance caused by the sluggish electrons/lithium transportation,irreversible phase changes,vanadium dissolution and large volume changes during the repeated lithium intercalation/deintercalation hinder their commercial development.Several optimizing routes have been carried out and extensively explored to address these problems.Taking V_(2)O_(5),VO_(2)(B),V_(6)O_(13),and V_(2)O_(3)as examples,this article reviewed their crystal structures and lithium storage reactions.Besides,recent progress in modification methods for the electrochemical insufficiencies of vanadium oxides,including nanostructure,heterogeneous atom doping,composite and self-supported electrodes has been systematically summarized and finally,the challenges for the industrialization of vanadium oxide cathodes and their development opportunities are proposed.

Process Optimization on Monascus Pigment Produced by Monascus

[Objective] This study was conducted to optimize rice making process and improve the content of Monascus pigment. [Method]Selecting water addition( A),sterilization temperature( B),sterilization time( C),soaking time( D) as experimental factors,L_9( 3~4) orthogonal test was carried out to optimize rice making process. [Result] The four factors all had very significant effect on the yield of Monascus pigment,the optimal combination was A_1B_2C_2D_2,namely water addition of 30 ml,sterilization temperature at 121 ℃,sterilization time of 23 min,and soaking time of 24 h. The level of Monascus reached 2 884 U/g under this condition. [Conclusion] The study has great practical significance to Monascus rice production enterprises.

Review on electrochemical carbon dioxide capture and transformation with bipolar membranes

Anthropogenic carbon dioxide(CO_(2))emission from the combustion of fossil fuels aggravates the global greenhouse effect.The implementation of CO_(2)capture and transformation technologies have recently received great attention for providing a pathway in dealing with global climate change.Among these technologies,electrochemical CO_(2)capture technology has attracted wide attention because of its environmental friendliness and flexible operating processes.Bipolar membranes(BPMs)are considered as one of the key components in electrochemical devices,especially for electrochemical CO_(2)reduction and electrodialysis devices.BPMs create an alkaline environment for CO_(2)capture and a stable pH environment for electrocatalysis on a single electrode.The key to CO_(2)capture in these devices is to understand the water dissociation mechanism occurring in BPMs,which could be used for optimizing the operating conditions for CO_(2)capture and transformation.In this paper,the references and technologies of electrochemical CO_(2)capture based on BPMs are reviewed in detail,thus the challenges and opportunities are also discussed for the development of more efficient,sustainable and practical CO_(2)capture and transformation based on BPMs.

Graphene-supported cobalt nanoparticles used to activate SiO_(2)-based anode for lithium-ion batteries

Although SiO_(2)-based anode is a strong competitor to supersede graphite anode for lithium-ion batteries,it still has problems such as low electrochemical activity, enormous loss of active lithium, and serious volume expansion. In order to solve these problems, we used a graphene network loaded with cobalt metal nanoparticles(rGO-Co) to coat SiO_(2) porous hollow spheres(SiO_(2)@rGO-Co). The construction of porous hollow structure and graphene network can shorten the lithium-ion(Li^(+)) diffusion distance and enhance the conductivity of the composite, which improves the electrochemical activity of SiO_(2) effectively. They also alleviate the volume expansion of the anode in the cycling process. Moreover,nano-scale cobalt metal particles dispersed on graphene catalyze the conversion reaction of SiO_(2) and activate the locked Li+in Li_(2)O through a reversible reaction, which improves the charge and discharge capacity of the anode. The capacity of SiO_(2)@rGO-Co reaches 370.4 m Ah/g after 100 cycles at 0.1 A/g,which is 6.19 times the capacity of pure SiO_(2)(59.8 mAh/g) under the same circumstance. What is more,its structure also exhibits excellent cycle stability, with a volume expansion rate of only 13.0% after 100 cycles at a current density of 0.1 A/g.

Dense ceramics with complex shape fabricated by 3D printing:A review

Three-dimensional(3D)printing technology is becoming a promising method for fabricating highly complex ceramics owing to the arbitrary design and the infinite combination of materials.Insufficient density is one of the main problems with 3D printed ceramics,but concentrated descriptions of making dense ceramics are scarce.This review specifically introduces the principles of the four 3D printing technologies and focuses on the parameters of each technology that affect the densification of 3D printed ceramics,such as the performance of raw materials and the interaction between energy and materials.The technical challenges and suggestions about how to achieve higher ceramic density are presented subsequently.The goal of the presented work is to comprehend the roles of critical parameters in the subsequent 3D printing process to prepare dense ceramics that can meet the practical applications.

MnS hollow microspheres combined with carbon nanotubes for enhanced performance sodium-ion battery anode

MnS as anode material for sodium-ion batteries(SIBs)has recently attracted great attention because of the high theoretical capacity,great natural abundance,and low cost.However,it suffers from inferior electrical conductivity and large volume expansion during the charge/discharge process,leading to tremendous damage of electrodes and subsequently fast capacity fading.To mitigate these issues,herein,a three-dimensional(3D)interlaced carbon nanotubes(CNTs)threaded into or between MnS hollow microspheres(hollow MnS/CNTs composite)has been designed and synthesized as an enhanced anode material.It can effectively improve the electrical conductivity,buffer the volume change,and maintain the integrity of the electrode during the charging and discharging process based on the synergistic interaction and the integrative structure.Therefore,when evaluated as anode for SIBs,the hollow MnS/CNTs electrode displays enhanced reve rsible capacity(275 mAh/g at 100 mA/g after 100 cycles),which is much better than that of pure MnS electrode(25 mAh/g at 100 mA/g after 100 cycles)prepared without the addition of CNTs.Even increasing the current density to 500 mA/g,the hollow MnS/CNTs electrode still delivers a five times higher reversible capacity than that of the pure MnS electrode.The rate performance of the hollow MnS/CNTs electrode is also superior to that of pure MnS electrode at various current densities from 50 mA/g to 1000 mA/g.

Methods for enhancing the capacity of electrode materials in low-temperature lithium-ion batteries

Lithium-ion batteries(LIBs)have evolved into the mainstream power source of ene rgy sto rage equipment by reason of their advantages such as high energy density,high power,long cycle life and less pollution.With the expansion of their applications in deep-sea exploration,aerospace and military equipment,special working conditions have placed higher demands on the low-temperature performance of LIBs.However,at low temperatures,the severe polarization and inferior electrochemical activity of electrode materials cause the acute capacity fading upon cycling,which greatly hindered the further development of LIBs.In this review,we summarize the recent important progress of LIBs in low-temperature operations and introduce the key methods and the related action mechanisms for enhancing the capacity of the various cathode and anode materials.It aims to promote the development of high-performance electrode materials and broaden the application range of LIBs.

Enhanced electrochemical performance of SnS nanoparticles/CNTs composite as anode material for sodium-ion battery

SnS nanoparticles/CNTs composite(SnS/CNTs composite) is synthesized by a facile one-pot solvothermal reaction. The structural characterizations reveal pure SnS nanoparticles with the size of less than 10 nm distribute on the surface of CNTs with the diameter of less than 20 nm. The SnS/CNTs composite electrode performs high reversible capacity and good cyclability(365 mAh/g at 50 mA/g after 50 cycles), which is superior to that of pure SnS electrode synthesized without the adding of CNTs(115.9 mAh/g at 50 mA/g after 50 mA/g cycles). Even increasing the current density to 500 mA/g, the SnS/CNTs composite electrode still delivers a reversible capacity up to 210 mAh/g after 100 cycles, nearly two times higher than that of the pure SnS electrode(108 mAh/g after 100 cycles). The rate performance of the SnS/CNTs composite electrode is also better than that of pure SnS electrode at different current densities from50 mA/g to 800 mA/g. The enhanced electrochemical performance of SnS/CNTs composite can be attributed to the adding of CNTs as a flexible and conductive structure supporter and the formation of SnS nanoparticles with small size. The SnS nanoparticles/CNTs composite structure not only benefits for buffering the volume change during charge and discharge process, but also increases the surface area for sufficient electrode-electrolyte contacting, and shortens Na^+ diffusion length, which improves the conductivity and stability of active material and finally provides desirable electrochemical performance.

Novel fast lithium-ion conductor LiTa_(2)PO_(8)enhances the performance of poly(ethylene oxide)-based polymer electrolytes in all-solid-state lithium metal batteries

At present,replacing the liquid electrolyte in a lithium metal battery with a solid electrolyte is considered to be one of the most powerful strategies to avoid potential safety hazards.Composite solid electrolytes(CPEs)have excellent ionic conductivity and flexibility owing to the combination of functional inorganic materials and polymer solid electrolytes(SPEs).Nevertheless,the ionic conductivity of CPEs is still lower than those of commercial liquid electrolytes,so the development of high-performance CPEs has important practical significance.Herein,a novel fast lithium-ion conductor material LiTa_(2)PO_(8) was first filled into poly(ethylene oxide)(PEO)-based SPE,and the optimal ionic conductivity was achieved by filling different concentrations(the ionic conductivity is 4.61×10^(-4)S/cm with a filling content of 15 wt%at 60℃).The enhancement in ionic conductivity is due to the improvement of PEO chain movement and the promotion of LiTFSI dissociation by LiTa_(2)PO_(8).In addition,LiTa_(2)PO_(8) also takes the key in enhancing the mechanical strength and thermal stability of CPEs.The assembled LiFePO_(4) solid-state lithium metal battery displays better rate performance(the specific capacities are as high as 157.3,152,142.6,105 and 53.1 mAh/g under0.1,0.2,0.5,1 and 2 C at 60℃,respectively)and higher cycle performance(the capacity retention rate is86.5%after 200 cycles at 0.5 C and 60℃).This research demonstrates the feasibility of LiTa_(2)PO_(8) as a filler to improve the performance of CPEs,which may provide a fresh platform for developing more advanced solid-state electrolytes.

Improving cycling stability of Bi-encapsulated carbon fibers for lithium/sodium-ion batteries by Fe_(2)O_(3) pinning

Bi draws increasing attention as anode materials for lithium-ion batteries and sodium-ion batteries due to its unique layered crystal structure,which is in favor of achieving fast ionic diffusion kinetics during cycling.However,the dramatic volume expansion upon lithiation/sodiation and an insufficient theoretical capacity of Bi greatly hinder its practical application.Herein,we report the Fe_(2 )O_(3) nanoparticle-pinning Bi-encapsulated carbon fiber composites through the electrospinning technique.The introduction of Fe_(2 )O_(3) nanoparticles can prevent the growth and aggregation of Bi nanoparticles during synthetic and cycling processes,re s pectively.Fe_(2)O_(3) with high specific capacity also contributes to the specific capacity of the composites.Consequently,the as-prepared Bi-Fe_(2)O_(3)/carbon fiber composite exhibits outstanding long-term stability,which delivers reversible capacities 504 and 175 mAh/g after1000 cycles at 1 A/g for lithium-ion and sodium-ion batteries,respectively.

Carbon-doped surface unsaturated sulfur enriched CoS2@rGO aerogel pseudocapacitive anode and biomass-derived porous carbon cathode for advanced lithium-ion capacitors

As a hybrid energy storage device of lithium-ion batteries and supercapacitors,lithium-ion capacitors have the potential to meet the demanding needs of energy storage equipment with both high power and energy density.In this work,to solve the obstacle to the application of lithium-ion capacitors,that is,the balancing problem of the electrodes kinetic and capacity,two electrodes are designed and adequately matched.For the anode,we introduced in situ carbon-doped and surface-enriched unsaturated sulfur into the graphene conductive network to prepare transition metal sulfides,which enhances the performance with a faster lithium-ion diffusion and dominant pseudocapacitive energy storage.Therefore,the lithium-ion capacitors anode material delivers a remarkable capacity of 810 mAh·g^(−1) after 500 cycles at 1 A·g^(−1).On the other hand,the biomass-derived porous carbon as the cathode also displays a superior capacity of 114.2 mAh·g^(−1) at 0.1 A·g^(−1).Benefitting from the appropriate balance of kinetic and capacity between two electrodes,the lithium-ion capacitors exhibits superior electrochemical performance.The assembled lithium-ion capacitors demonstrate a high energy density of 132.9 Wh·kg^(−1) at the power density of 265 W·kg^(−1),and 50.0 Wh·kg^(−1) even at 26.5 kW·kg^(−1).After 10000 cycles at 1 A·g^(−1),lithium-ion capacitors still demonstrate the high energy density retention of 81.5%.