Succinimide-modified graphite as anode materials for lithium-ion batteries

A comprehensive review of various carbonaceous materials for anodes in lithium-ion batteries

With the advent of lithium-ion batteries (LIBs), the selection and application of electrode materials have been the subject of much discussion and study. Among them, graphite has been widely investigated for use as electrode materials in LIBs due to its abundant resources, low cost, safety and electrochemical diversity. While it is commonly recognized that conventional graphite materials utilized for commercial purposes have a limited theoretical capacity, there has been a steady emergence of new and improved carbonaceous materials for use as anodes in light of the progressive development of LIBs. In this paper, the latest research progress of various carbon materials in LIBs is systematically and comprehensively reviewed. Firstly, the rocking chair charging and discharging mechanism of LIBs is briefly introduced in this paper, using graphite anodes as an example. After that, the general categories of carbonaceous materials are highlighted, and the recent research on the recent progress of various carbonaceous materials (graphite-based, amorphous carbon-based, and nanocarbon-based) used in LIB anodes is presented separately based on the classification of the structural morphology, emphasizing the influence of the morphology and structure of carbon-based materials on the electrochemical performance of the batteries. Finally, the current challenges of carbonaceous materials in LIB applications and the future development of other novel carbonaceous materials are envisioned.

Improving Natural Microcrystalline Graphite Performances by a Dual Modification Strategy toward Practical Application of Lithium Ion Batteries

Microcrystalline graphite (MG), as a kind of natural graphite (NG), holds great potential for use as an anode material for lithium-ion batteries (LIBs) due to low raw material cost, good electrolyte compatibility, and relatively long cycle life. Nevertheless, the relatively low reversible capacity and poor initial Coulombic efficiency (ICE) of the MG anode largely limit its practical application in LIBs. In order to improve the lithium storage capacity of MG, three kinds of oxidant intercalators are applied to treat the original MG, and the as-obtained MG is further modified by a thin carbon layer. The results indicate that using H2SO4-C2H2O4 as oxidant intercalators and subsequent carbon coating layer modification are the optimum techniques, and they can increase the interlayer distance, introduce defects to decrease the volume expansion, and generate channels for fast Li+ diffusion. Meanwhile, the carbon coating layer can reduce the specific surface area of graphite and greatly improve the ICE and cycling performance. Especially, the OEMGC-2 anodes prepared by the dual modification strategies represent a high reversible capacity of 349.4 mA h g-1 at 0.2C with a satisfactory ICE of 90.2%, indicating that the MG can also be considered as a high performance and low-cost anode material of LIBs.

Hofmann Ni-Pz-Ni Metal-Organic Frameworks Decorated by Graphene Oxide Enabling Lithium Storage with Pseudocapacitance Contribution

Hofmann metal-organic frameworks (MOFs) are a variety of hybrid inorganic-organic polymers with a stable framework, plentiful adjustable pore size, and redox active sites, which display great application potential in energy storage. Unfortunately, the rapid and uncontrollable rate of coordination reaction results in a large size and an anomalous morphology, and the low electrical conductivity also severely limited further development, so there are few literature studies on Hofmann MOFs as anode materials for rechargeable batteries. Introducing graphene oxide can not only greatly facilitate the formation of a continuous conductive network but also effectively anchor and disperse MOF particles by utilizing the two-dimensional planar structure, thus reducing the sizes and agglomeration of particles. In this work, various mass ratios of graphene oxide with 3D Hofmann Ni-Pz-Ni MOFs were prepared via a simple one-pot solvothermal method. Benefiting from the gradually increasing capacitance characteristic during the continuous charge/discharge process, the Ni-Pz-Ni/GO-20% electrode exhibits a great reversible capacity of 896.1 mAh g^-1 after 100 cycles and excellent rate capability, which will lay a theoretical foundation for exploring the high-performance Hofmann MOFs in the future.

Graphene composite 3,4,9,10-perylenetetracarboxylic sodium salts with a honeycomb structure as a high performance anode material for lithium ion batteries

In order to address the issues of high solubility in electrolytes, poor conductivity and low active site utilization of organic carbonyl electrode materials, in this work, the 3,4,9,10-perylenetetracarboxylic sodium salt (PTCDA-Na) and its graphene composite PTCDA-Na-G are prepared by the hydrolysis of 3,4,9,10-perylenetetracarboxylic dianhydride and the strategy of antisolvent precipitation. The obtained PTCDA-Na active substance has a porous honeycomb structure, showing a large specific surface area. Moreover, after recombination with graphene, the dispersion and specific surface area of PTCDA-Na are further enhanced, and more active sites are exposed and conductivity is improved. As a result, the PTCDA-Na-G composite electrode materials exhibit superior electrochemical energy storage behaviors. The initial charge capacity of the PTCDA-Na-G electrode is 890.5 mA h g-1, and after 200 cycles, the capacity can still remain at 840.0 mA h g-1 with a high retention rate of 94.3%, which is much larger than those of the PTCDA-Na electrode. In addition, at different current densities, the PTCDA-Na-G electrode also presents higher capacities and better cycle stability than the PTCDA-Na electrode. Compared with PTCDA-Na with a porous honeycomb structure and previously reported sodium carboxylic acid salts with a large size bulk structure, the PTCDA-Na-G composite material prepared in this work shows superior electrochemical energy storage properties due to its large specific surface area, high dispersion, more exposed active sites and large electrical conductivity, which would provide new ideas for the development of high performance organic electrode materials for lithium-ion batteries.