Mengqiu Jia

Nitrogen-Rich Mesoporous Carbon as Anode Material for High-Performance Sodium-Ion Batteries.

Nitrogen-rich carbon with interconnected mesoporous structure has been simply prepared via a nano-CaCO3 template method, using polyaniline as carbon and nitrogen precursors. The preparation process includes in situ polymerization of aniline in a nano-CaCO3 aqueous solution, carbonization of the composites and removal of the template with diluted hydrochloric acid. Nitrogen sorption shows the carbon-enriched mesopores with a specific surface area of 113 m(2) g(-1). The X-ray photoelectron spectroscopy (XPS) analysis indicates that the carbon has a high nitrogen content of 7.78 at. %, in the forms of pyridinic and pyrrolic, as well as graphitic nitrogen. The nitrogen-rich mesoporous carbon shows a high reversible capacity of 338 mAh g(-1) at a current density of 30 mA g(-1), and good rate performance as well as ultralong cycling durability (110.7 mAh g(-1) at a current density of 500 mA g(-1) over 800 cycles). The excellent sodium storage performance of the nitrogen-rich mesoporous carbon is attributed to its disordered structure with large interlayer distance, interconnected porosity, and the enriched nitrogen heteroatoms.

Creative utilization of natural nanocomposites: nitrogen-rich mesoporous carbon for a high-performance sodium ion battery

A resource-abundant, low-cost and high-performance anode is indispensable to the future success of sodium ion batteries (SIBs) for applications in large-scale energy storage. Animal byproducts are naturally pre-organized organic/inorganic nanocomposite materials composed of collagen and nanominerals. Making the best use of these natural nanocomposites is a good choice to develop carbon anodes for SIBs. Here, using shrimp skin as an example, we demonstrated a simple preparation of nitrogen-rich mesoporous carbon materials from natural nanocomposites and used these carbon materials for developing high-performance SIBs. Collagen was used as a nitrogen-rich precursor of the carbon, while the nanominerals, distributed evenly in the collagen matrix, acted as a hard template to create mesopores. The shrimp skin was subjected to direct pyrolysis under an inert atmosphere followed by removal of minerals, and was hence easily transformed into nitrogen-rich mesoporous carbons subsequently shown to serve as high-performance sodium storage materials. In this way, we turned “trash” into “treasure”. The unique microstructure of the nitrogen-rich mesoporous carbon resulted in its exhibiting outstanding performances as anodes for SIBs. The reversible sodium storage capacity reached as high as 434.6 mA h g−1 at 30 mA g−1 with excellent cycle durability and rate capability. These results indicated the creative utilization of the natural nanocomposites to be a facile, sustainable strategy for the synthesis of high-performance sodium storage materials.

A floral variant of mesoporous carbon as an anode material for high performance sodium and lithium ion batteries

The floral variant of mesoporous carbon was simply prepared by direct pyrolysis of zinc citrate followed by washing with dilute hydrochloric acid. The unique floral microstructure endows the carbon with ultrahigh reversible capacity, excellent cycle stability and superior rate performance as an anode material for both sodium ion batteries and lithium ion batteries. The floral variant of mesoporous carbon exhibits a reversible sodium storage capacity as high as 438.5 mA h g−1 at a current density of 30 mA g−1 and retains a value of 68.7 mA h g−1 at an enhanced current density of 10 A g−1. Moreover, the floral mesoporous carbon can deliver a tremendous reversible capacity up to 1370 mA h g−1 at 50 mA g−1 as an anode for lithium ion batteries. It can output a high reversible capacity of 222 mA h g−1 even when being charged and discharged at 50 A g−1. Based on the astounding capacity and rate performance, the floral variant of mesoporous carbon can be regarded as one of the most promising anode materials for both sodium-ion and lithium-ion batteries.

1D ultrafine SnO2 nanorods anchored on 3D graphene aerogels with hierarchical porous structures for high-performance lithium/sodium storage

SnO2 is considered as one of the most promising alternative anode materials for lithium ion batteries (LIBs) and sodium ion batteries (SIBs) due to high specific capacity, low discharge voltage plateau and environmental friendliness. In this work, 1D ultrafine SnO2 nanorods anchored on 3D graphene aerogel (SnO2 NRs/GA) composite is prepared through a simple reduction-induced self-assembly method in the solution of graphene oxide (GO), Vitamin C and SnO2 nanoparticles. Vitamin C plays an important role in the reduction of GO. The structural and morphological characterizations demonstrate that 1D ultrafine SnO2 nanorods are uniformly and tightly anchored on the surface of 3D graphene nanosheet aerogels. The unique 3D network structure as well as the synergistic effect between 3D graphene nanoshhet and 1D SnO2 nanorods endows the as-prepared SnO2 NRs/GA composite with the good electrochemical lithium/sodium storage performance. It delivers the high initial discharge capacity (1713 mA h g-1 at 0.1 A g-1 for LIBs and 539 mA h g-1 at 0.05 A g-1 for SIBs) and good cycle stability (869 mA h g-1 at 0.1 A g-1 after 50 cycles for LIBs and 232 mA h g-1 at 0.05 A g-1 after 100 cycles for SIBs). Moreover, the SnO2 NRs/GA composite exhibits excellent cycle stability for SIBs with a high reversible capacity of 96 mA h g-1 at as high as 1 A g-1 for 500 cycles. This work provides a simple method to fabricate the electro-active materials-graphene aerogel composites for high-performance LIBs and SIBs.