Cost-Effective Biomass Carbon/Calix[4]Quinone Composites for Lithium Ion Batteries

Carbonyl Chemistry for Advanced Electrochemical Energy Storage Systems

On the basis of the sustainable concept, organic compounds and carbon materials both mainly composed of light C element have been regarded as powerful candidates for advanced electrochemical energy storage (EES) systems, due to theie merits of low cost, eco-friendliness, renewability, and structural versatility. It is investigated that the carbonyl functionality as the most common constituent part serves a crucial role, which manifests respective different mechanisms in the various aspects of EES systems. Notably, a systematical review about the concept and progress for carbonyl chemistry is beneficial for ensuring in-depth comprehending of carbonyl functionality. Hence, a comprehensive review about carbonyl chemistry has been summarized based on state-of-the-art developments. Moreover, the working principles and fundamental properties of the carbonyl unit have been discussed, which has been generalized in three aspects, including redox activity, the interaction effect, and compensation characteristic. Meanwhile, the pivotal characterization technologies have also been illustrated for purposefully studying the related structure, redox mechanism, and electrochemical performance to profitably understand the carbonyl chemistry. Finally, the current challenges and promising directions are concluded, aiming to afford significant guidance for the optimal utilization of carbonyl moiety and propel practicality in EES systems.

Carbon Nanotube-encapsulated Chestnut Inner Shell O,N-doped Graded Porous Carbon as Stable and High-Sulfur Loading Electrode for Lithium-Sulfur Batteries

The shuttle effect of lithium-sulfur (Li-S) batteries and the poor conductivity of sulfur (S) and lithium polysulfide severely limit their practical applications. Currently, compounding carbon materials with S is one of the effective ways to solve this problem. Therefore, green, low-cost chestnut inner shell biochar (CISC) with graded porous structure was used as the S carrier in this experiment, and carbon nanotubes (CNTs) coating was employed as the S protective layer to improve the electrical conductivity and inhibit the shuttle effect. The results showed that the CISC prepared in this experiment had a relatively high specific surface area (1135.11 m2  g-1 ), and the S loading rate was as high as 65.72 %. The graded porous structure and high specific surface area of CISC can increase the loading rate of S and thus increase the battery capacity. Meanwhile, the naturally contained O and N elements can improve the chemisorption of S. The initial discharge capacity of the CISC@S/CNTs battery at 0.1 C is 967.3 mAh g-1 , and the capacity retention rate is 74.3 % after 500 cycles. The unique composite structure improves the battery's electrical conductivity, reduces the dissolution of polysulfides, and enhances the battery cycle stability.

Recent Advance in Ionic-Liquid-Based Electrolytes for Rechargeable Metal-Ion Batteries

From basic research to industry process, battery energy storage systems have played a great role in the informatization, mobility, and intellectualization of modern human society. Some potential systems such as Li, Na, K, Mg, Zn, and Al secondary batteries have attracted much attention to maintain social progress and sustainable development. As one of the components in batteries, electrolytes play an important role in the upgrade and breakthrough of battery technology. Since room-temperature ionic liquids (ILs) feature high conductivity, nonflammability, nonvolatility, high thermal stability, and wide electrochemical window, they have been widely applied in various battery systems and show great potential in improving battery stability, kinetics performance, energy density, service life, and safety. Thus, it is a right time to summarize these progresses. In this review, the composition and classification of various ILs and their recent applications as electrolytes in diverse metal-ion batteries (Li, Na, K, Mg, Zn, Al) are outlined to enhance the battery performances.

Recent advances of covalent organic frameworks in lithium ion batteries

This review divides the active sites of COFs into four categories: carbonyl, phenyl, imine bonds and other groups, and introduces their applications in LIBs.

Overview of the Synthesis and Structure of Calix[n]quinones (n=4, 6, 8)

Calix[n]quinones, a class of cyclic oligomers composed of p-benzoquinone structures connected by methylene, have multi-conjugated carbonyl structures and adjustable cavities, which make their synthesis extremely attractive. In this minireview, synthetic methods of calix[n]quinones and recent synthetic experience of our group are summarized. The merits and demerits of various synthetic methods are briefly reviewed as well. When synthesizing calix[n]quinone (n≥6) with a larger ring, the reduction-oxidation method is considered to be the most recommended.