STUDY ON INTERCALATION MECHANISM OF GELATIN/MMT NANOCOMPOSITE

A gelatin/MMT nanocomposite was prepared in an aqueous solution and investigated by XRD,FTIR and 13 C NMR,and then the intercalation mechanism was discussed.The result of XRD indicated that the gelatin molecule had already inserted into the interlayer of MMT,and the intercalation or exfoliation structure had been achieved.The result of 13 C NMR demonstrated that the ions interaction between gelatin and MMT was attributed to the driving force for intercalation.In order to confirm the role of -COO - of gelatin in the combination with MMT,lauric sodium was brought in as a model to react with MMT,and was characterized by XRD and FTIR,the result proved that there existed a kind of strong interaction between -COO - and ions of MMT.

Experimental study of motion characteristics of rock slopes with weak intercalation under seismic excitation

In order to investigate the effect of a weak intercalation on slope stability, a large-scale shaking table model test was conducted to study the dynamic response of rock slope models with weak intercalation.The dynamic response of the prototype slopes were studied in laboratory with the consideration of law of similitude. The initiation failure was observed in the rock slope model with a counter-tilt thin-weak intercalation firstly, not in the slope model with a horizontal thin-weak intercalation. Furthermore, it was interesting that the fracture site is shifted from crest top to the slope surface near the weak intercalation, which is different with the location of failure position in a normal layered slope. We also discussed the effect of the dip angle and the thickness of weak intercalation on the failure mechanism and instability mode of the layered rock slope. From the experimental result, it was noted that the stability of the slope with a counter-tilt weak intercalation could be worse than that of the other slopes under seismic excitation. The findings showed the difference of failure in slopes with a horizontal and counter weak intercalation, and implicated the further evaluation of failure of layered slopes caused by seismic loads.

Cu_(3)P nanoparticles confined in nitrogen/phosphorus dual-doped porous carbon nanosheets for efficient potassium storage

Immobilizing primary electroactive nanomaterials in porous carbon matrix is an effective approach for boosting the electrochemical performance of potassium-ion batteries (PIBs) because of the synergy among functional components. Herein, an integrated hybrid architecture composed of ultrathin Cu_(3)P nanoparticles (~20 nm) confined in porous carbon nanosheets (Cu_(3)P⊂NPCSs) as a new anode material for PIBs is synthesized through a rational self-designed self-templating strategy. Benefiting from the unique structural advantages including more active heterointerfacial sites, intimate and stable electrical contact, effectively relieved volume change, and rapid K^(+) ion migration, the Cu_(3)P⊂NPCSs indicate excellent potassium-storage performance involving high reversible capacity, exceptional rate capability, and cycling stability. Moreover, the strong adsorption of K^(+) ions and fast potassium-ion reaction kinetics in Cu_(3)P⊂NPCSs is verified by the theoretical calculation investigation. Noted, the intercalation mechanism of Cu_(3)P to store potassium ions is, for the first time, clearly confirmed during the electrochemical process by a series of advanced characterization techniques.

Yolk-shell nanoarchitecture for stabilizing a Ce_(2)S_(3)anode

Rare-earth sulfides are of research interest for lithium-ion batteries(LIBs)due to their abundant lithium intercalation sites and low redox voltage.However,their electrochemical performances are not satisfactory because of poor conductivity and volume change upon electrochemical cycling.Herein,nanoarchitectures ofγ-Ce_(2)S_(3)encapsulated in a hollow mesoporous carbon nanosphere(Ce_(2)S_(3)@HMCS)are fabricated using the self-template strategy combined with the in-sphere sulfuration method and tested as an LIB anode.The void space between the Ce_(2)S_(3)core and the outer layer of the carbon nanosphere has been properly designed and modulated to achieve excellent electrochemical performance in terms of electronic conductivity,reversibility,and rate capability.The reversible capacity of Ce_(2)S_(3)@HMCS is 2.6 times that of the pure Ce_(2)S_(3)anode,which can gradually increase and maintain a capacity of 282 mAh·g^(−1)at a current density of 1 A·g^(-1),and a high Coulombic efficiency(~100%)can be achieved even after 1000 cycles.This good performance is attributed to the unique yolk-shell nanostructure with a highly crystallized and stable Ce3S2 core and volume expansion buffer space upon lithiation/delithiation.Ex situ X-ray diffraction and nuclear magnetic resonance results indicate that the lithiation of Ce_(2)S_(3)@HMCS is an intercalation process.This study represents an important advancement in precise structural design with in-sphere sulfuration and sheds light on a potential direction for highperformance lithium storage.

Fluorophosphates and fluorosulfates cathode materials: Progress towards high energy density sodium-ion battery

The rapid diffusion of renewable energy boosts the wide deployment of large-scale energy storage system.With the low cost and high crustal abundance,sodium-ion battery(SIB)technology is expected to become a dominant technology in that area in the future.Toward the practical application,novel cathode materials are urged to develop that show high energy density without sacrificing their cost and benignity to the environment.While the years of many studies,this still remains a huge challenge to battery scientists.In this review,we discuss recent breakthroughs in SIB cathode materials with high energy density,namely fluorphosphates and fluorosulfates.The design of materials,the crystal structure,the electrochemical performance,and the underlaying intercalation mechanism are systematically reviewed.Useful strategies and research directions are also provided to advance future high-energy,low-cost,and ecofriendly cathode materials for next generation SIB.

Non-aqueous Al-ion batteries:cathode materials and corresponding underlying ion storage mechanisms

Aluminum-ion batteries(AIBs)are recognized as one of the promising candidates for future energy stor-age devices due to their merits of cost-effectiveness,high voltage,and high-power operation.Many efforts have been devoted to the development of cathode materials,and the progress has been well summarized in this review paper.Moreover,in addition to materials,the intercalation mechanism also plays a key role in determining cell per-formance.Here,the research progress of cathode materials and corresponding ion intercalation mechanism in AIBs are summarized,including intercalation of AlCl_(4)-,intercala-tion of Al^(3+),and coordination of AlCl_(2)^(+)/AlCl^(2+).This minireview provides comprehensive guidance on the design of cathode materials for the development of high-performance AIBs.