DFT‑Guided Design and Fabrication of Carbon‑Nitride‑Based Materials for Energy Storage Devices:A Review

Carbon nitrides(including CN,C2N,C3N,C3N4,C4N,and C5N)are a unique family of nitrogen-rich carbon materials with multiple beneficial properties in crystalline structures,morphologies,and electronic configurations.In this review,we provide a comprehensive review on these materials properties,theoretical advantages,the synthesis and modification strategies of different carbon nitride-based materials(CNBMs)and their application in existing and emerging rechargeable battery systems,such as lithium-ion batteries,sodium and potassium-ion batteries,lithium sulfur batteries,lithium oxygen batteries,lithium metal batteries,zinc-ion batteries,and solid-state batteries.The central theme of this review is to apply the theoretical and computational design to guide the experimental synthesis of CNBMs for energy storage,i.e.,facilitate the application of first-principle studies and density functional theory for electrode material design,synthesis,and characterization of different CNBMs for the aforementioned rechargeable batteries.At last,we conclude with the challenges,and prospects of CNBMs,and propose future perspectives and strategies for further advancement of CNBMs for rechargeable batteries.

Polar, catalytic, and conductive CoSe2/C frameworks for performance enhanced S cathode in Li–S batteries

Lithium-sulfur battery(Li-S)is considered as one of the new-generation rechargeable batteries with high performance because of its extremely high theoretical capacity,energy density,environmental harmony and low cost.However,low electrical and ionic conductivity of sulfur,safety concerns and parasitic reaction generated by the dissolved polysulfide species in electrolyte hinder the commercialization of Li-S battery.Herein,we report a polyhedral porous structure comprising of carbon coating metal selenide nanoparticles(CoSe2/C),which could not only host sulfur for Li-S battery owing to its porous and conductive structure,but also mitigate the shuttle phenomenon by polysulfides adsorption and catalytic acceleration of redox kinetics.As a result,a performance enhanced CoSe2/C-S electrode for Li-S battery is achieved.

Interface Engineering via Ti_(3)C_(2)T_(x) MXene Electrolyte Additive toward Dendrite-Free Zinc Deposition

Zinc metal batteries have been considered as a promising candidate for next-generation batteries due to their high safety and low cost.However,their practical applications are severely hampered by the poor cyclability that caused by the undesired dendrite growth of metallic Zn.Herein,Ti_(3)C_(2)T_(x) MXene was first used as electrolyte additive to facilitate the uniform Zn deposition by controlling the nucleation and growth process of Zn.Such MXene additives can not only be absorbed on Zn foil to induce uniform initial Zn deposition via providing abundant zincophilic-O groups and subsequently participate in the formation of robust solid-electrolyte interface film,but also accelerate ion transportation by reducing the Zn^(2+) concentration gradient at the electrode/electrolyte interface.Consequently,MXene-containing electrolyte realizes dendrite-free Zn plating/striping with high Coulombic efficiency(99.7%)and superior reversibility(stably up to 1180 cycles).When applied in full cell,the Zn-V_(2)O_(5)cell also delivers significantly improved cycling performances.This work provides a facile yet effective method for developing reversible zinc metal batteries.

Highly Reversible Li–Se Batteries with Ultra-Lightweight N,S-Codoped Graphene Blocking Layer

The desire for practical utilization of rechargeable lithium batteries with high energy density has motivated attempts to develop new electrode materials and battery systems. Here, without additional binders we present a simple vacuum filtration method to synthesize nitrogen and sulfur codoped graphene(N,S-G) blocking layer, which is ultra-lightweight, conductive, and free standing. When the N,S-G membrane was inserted between the catholyte and separator, the lithium–selenium(Li–Se)batteries exhibited a high reversible discharge capacity of 330.7 mAh g^(-1) at 1 C(1 C = 675 mA g^(-1)) after 500 cycles and high rate performance(over 310 mAh g^(-1) at 4 C) even at an active material loading as high as ～5 mg cm^(-2). This excellent performance can be ascribed to homogenous dispersion of the liquid active material in the electrode, good Li^+-ion conductivity, fast electronic transport in the conductive graphene framework, andstrong chemical confinement of polyselenides by nitrogen and sulfur atoms. More importantly, it is a promising strategy for enhancing the energy density of Li–Se batteries by using the catholyte with a lightweight heteroatom doping carbon matrix.

Poly(thiourea triethylene glycol) as a multifunctional binder for enhanced performance in lithium-sulfur batteries

A mechanically strong binder with polar functional groups could overcome the dilemma of the large volume change during charge/discharge processes and poor cyclability of lithium-sulfur batteries(LSBs).In this work,for the first time,we report the use of poly(thiourea triethylene glycol)(PTTG)as a multifunctional binder for sulfur cathodes to enhance the performance of LSBs.As expected,the PTTG binder facilitates the high performance and stability delivered by the Sulfur-PTTG cathode,including a higher reversible capacity of 825 mAh g^(-1) at 0.2 C after 80 cycles,a lower capacity fading(0.123%per cycle)over 350 cycles at 0.5 C,a higher areal capacity of 2.5 mAh cm^(-2) at 0.25 mA cm^(-2),and better rate capability of 587 mAh g^(-1) at 2 C.Such superior electrochemical performances could be attributed to PTTG's strong chemical adsorption towards polysulfides which may avoid the lithium polysulfide shuttle effect and excellent mechanical characteristics which prevents electrode collapse during cycling and allows the Sulfur-PTTG electrode to maintain robust electron and ion migration pathways for accelerated redox reaction kinetics.

Defect-rich and highly porous carbon nanosheets derived from Ti_(3)AlC_(2) MAX with good lithium storage properties

Defect-rich,highly porous two-dimensional carbon nanosheets(CNS) have attracted tremendous research interests in catalysis and environmental purification and other fields,because of their unique micromorphology,chemical stability and high specific surface area.Herein,in this work,we report a new solution to synthesize an ultrathin two-dimensional CNS with rich defects and abundant pores via two-step etching the Ti_(3)AlC_(2)with the help of I2and NaOH.The CNS thickness,specific surface area and pore volume could be all tunable by adding the amount of I2.And the highest specific surface area and pore volume of the synthesized 2D CNS can be achieved 1134.4 m^(2)/g and 0.80 cm^(3)/g,with a thickness of only 0.64 nm and a yield of 35.9%.When employed as the anodes for lithium-ion batteries,the synthesized CNS anodes exhibit good cycling and rate capabilities.This work provides a novel and facile strategy for synthesizing highly porous and defective 2D carbon materials with good lithium storage properties.

Catalytic conversion of biomass-derived compounds to various amino acids: status and perspectives

Amino acids are important nitrogen-containing chemicals that have a variety of applications.Currently,fermentation is the widely employed method to produce amino acids;however,the products are mostly limited to natural amino acids in the L-configuration.Catalytic synthesis is an alternative approach for the synthesis of amino acids with different types and configurations,where the use of renewable biomass-based feedstocks is highly attractive.To date,several lignocellulose and triacylglycerol-derived intermediates,typicallyα-keto acids andα-hydroxyl acids,have been transformed into amino acids via the amination reaction in the presence of additional nitrogen sources(i.e.,NH3·H2O).Making full use of inherent nitrogen in biomass(i.e.,chitin and protein)to produce amino acids avoids the use of extra nitrogen sources and meets the requirements of green chemistry,which is attracting increasing attention.In this review,we summarize different chemical-catalytic systems for the transformation of biomass to amino acids.An outlook on the challenges and opportunities for more effective production of amino acids from biomass by catalytic methods is provided.

Microporous bamboo biochar for lithium-sulfur batteries

简单、便宜、可伸缩、环境地友好，多微孔的生物资源 biochars 在锂硫(Li-S ) 为申请一直在吸引热心注意电池。此处，多孔的竹子 biochar 经由创造多微孔的结构的一个 KOH/annealing 过程被激活，增加表面区域并且提高电子电导率。对待的样品被用来包含硫准备多微孔的竹子碳硫(英国计算机学会) 用作为 Li-S 电池的阴极的 nanocomposite 第一次。有 50 wt.% 硫内容的英国计算机学会 nanocomposite 交付 1,295 妈的一个高起始的能力 ???  ??

SOCS3 Attenuates GM-CSF/IFN-γ-Mediated Inflammation During Spontaneous Spinal Cord Regeneration

SOCS3,a feedback inhibitor of the JAK/STAT signal pathway,negatively regulates axonal regrowth and inflammation in the central nervous system(CNS).Here,we demonstrated a distinct role of SOCS3 in the injured spinal cord of the gecko following tail amputation.Severing the gecko spinal cord did not evoke an inflammatory cascade except for an injury-stimulated elevation of the granulocyte/macrophage colony-stimulating factor(GM-CSF) and interferon gamma(IFN-γ) cytokines.Simultaneously,the expression of SOCS3 was upregulated in microglia,and unexpectedly not in neurons.Enforced expression of SOCS3 was sufficient to suppress the GMCSF/IFN-γ-driven inflammatory responses through its KIR domain by attenuating the activities of JAK1 and JAK2.SOCS3 was also linked to GM-CSF/IFN-y-induced crosstolerance.Transfection of adenovirus overexpressing SOCS3 in the injured cord resulted in a significant decrease of inflammatory cytokines.These results reveal a distinct role of SOCS3 in the regenerating spinal cord,and provide new hints for CNS repair in mammals.

Graphene-Based Sulfur Composites for Energy Storage and Conversion in Li-S Batteries

There are growing research interests in developing high-performance energy storage systems to meet the demands for large-scale and sustainable energy storage. The lithium-sulfur （Li-S） batteries have drawn numerous attentions due to their exceptionally high energy density compared with other batteries. However, achieving the high capacities with long-term cycle stability and retaining an essentially high sulfur loading remains a tremendous chal- lenge for the designs of Li-S batteries. Graphene is regarded as a very suitable and promising addition to the com- positions for Li-S batteries due to its unique two dimensional （2D） structure, high conductivity and superior me- chanical flexibility. Besides, the functional groups of graphene surface can be tuned flexibly to immobilize the S/Li2Sx on the graphene surface during the cycling process. In this review, the development of graphene-sulfur composites and their applications in Li-S batteries are discussed. The attempts are also devoted to the synthesis approaches of various graphene-based sulfur composites, the graphene-sulfur interaction and the impacts on the elec- trochemical performances as well as the major issues of Li-S batteries.

Water Reducer: A Highly Dispersing Binder for High-Performance Lithium-Sulfur Batteries

Sulfur has been paid close attention by the research and manufacturing as a cathode material for lithium-sulfur batteries(LSB)in recent decade because it has high specific capacity and low cost.But the low utilization of active materials and serious shuttle phenomenon inhibit its commercialization process.In this work,for the first time,water reducers are reported as multifunctional binders to address the above problems to enhance the performance of LSB.Due to the synthetic actions of the water reducer binder,such as highly dispersing effect and good chemical trapping function,commercial sulfur powders are directly used as cathodes,and much better electrochemical performance compared to using the conventional binder polyvinylidene fluoride(PVDF)was obtained,among which the sulfur cathode with sulfonated melamine formaldehyde(SMF)water reducer binder exhibits a high reversible capacity of 625.5 mA·h·g^(-1) after 200 cycles at 1 C and the cathode with polycarboxylic acid(PC)water reducer binder even demonstrates a high area specific capacity of 5 mA·h·cm^(-2) at high sulfur loading of 5 mg·cm^(-2).These low-cost water reducers are a promising binder for LSB in the future.