CARBON
·
2024
·
IF 10.5
Peng Zhou,Liang Pang,Yang Li,Huachan Fang,Peng Xiao,Feixiang Wu
The fabrication of three-dimensional (3D) honeycomb carbon frameworks, incorporating embedded silicon (Si) nanoparticles (NPs), is successfully achieved through a facile method involving mixing, carbonization , and acid pickling. The as-prepared Si@PVPC composites exhibit excellent electrochemical performances due to reasons as follows. (1) Honeycomb channels supply enough space to accommodate the expansion of Si NPs and so structural integrity of 3D honeycomb carbon frameworks are maintained during lithiation/delithiation processes. (2) Honeycomb channels offers fast transfer paths for Li-ion diffusion. (3) 3D carbon frameworks afford reliable and stable electric contact points. As a result, Si@PVPC electrodes show a capacity of 1294.3 mAh g −1 at 2 A g −1 after 1400 cycles with a capacity retention of 85.5 %. Even at an ultrahigh current of 16 A g −1 , Si@PVPC electrodes still show a capacity of 619.6 mAh g −1 .
研究领域:
材料科学
·
能源存储
✓ 已验证
DOI
高影响因子
RSC Advances
·
2021
·Vol. 11
·期 46
·28535-28541
·
IF 3.361
Peng Wang,Mingzhi Wang,Jianqiao Lu
Direct conversion of CO2 to high value-added carbon products based on molten salt electrochemistry has been proven to be a feasible approach to solve the climate problem and achieve carbon neutrality. In this work, carbon nanotubes (CNTs), carbon spheres (CSs) and honeycomb carbon are synthesized by electrolysis of a single or multiple alkali metal carbonate electrolyte. The elemental composition, morphology and structure, crystallinity and graphitization degree of carbon products are characterized by electron dispersive spectroscopy (EDS), scanning electron microscopy (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD) and Raman microspectroscopy (RAM). The results demonstrate that a high yield of CNTs is obtained in Li2CO3 electrolyte by regulating the electrolysis temperature and current density. Compared to pure Li2CO3, Li–Na carbonate electrolyte with 1 wt% stannic oxide/cerium oxide (SnO2/GeO2) favors CS formation rather than CNT formation. Additionally, honeycomb carbon products are generated in Li–Na–K electrolyte, when the electrolysis temperature is lower than 600 °C. Overall, this work provides a novel carbon neutral strategy where high value-added carbon products are synthesized using CO2 as a carbon source.
研究领域:
材料科学
·
环境科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Dengyang Wang,Qing Wang,Mingxiu Tan,Shasha Wang,Shaohua Luo,Pengqing Hou,Yahui Zhang,Shengxue Yan,Xin Liu
Carbon quantum dots (CQDs) as a multifunctional carbon nanomaterial have drawn great attention in the field of energy attribute to quantum size, various functional groups and unique physicochemical properties. In this work, the CQDs were prepared from soybean by a simple hydrothermal method , then further pyrolyzed into honeycomb carbon (HC), spherical pore carbon (SC) and bulk porous carbon (BC) with the assistance of templates, respectively. As the anode materials in potassium ion battery (PIBs), HC delivered a high specific capacity of 280.5 mAh g −1 at 0.1 A g −1 and a superior rate performance (136 mAh g −1 at 5 A g −1 ), ascribing to its abundant surface active sites of potassium ion storage and special structures conducive to potassium ion diffusion. This study provides an excellent anode for PIBs from a simple route to construct CQDs-derived carbon.
研究领域:
材料科学
·
能源存储
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2014
·
IF 4.086
Yaohui Qu,Zhian Zhang,Xiahui Zhang,Guodong Ren,Xiwen Wang,Yanqing Lai,Yexiang Liu,Jie Li
Sulfur has a high specific capacity of 1675 mAh g −1 as lithium battery cathode, but its rapid capacity fading due to polysulfides dissolution presents a significant challenge for practical applications. Here we report a novel hierarchical porous honeycomb carbon (HPHC) for lithium-sulfur battery cathode with effective trapping of polysulfides. The HPHC was prepared by a simple template process, and a sulfur-carbon composite based on HPHC was synthesized for lithium-sulfur batteries by a melt-diffusion method. It is found that the elemental sulfur was dispersed inside the three-dimensionally hierarchical pores of HPHC based on the analyses. Electrochemical tests reveal that the sulfur-HPHC composite shows high rate capability and long cycling stability as cathode materials. The sulfur-HPHC composite with sulfur content of 66.3 wt% displays an initial discharge capacity of 923 mAh g −1 and a reversible discharge capacity of 564 mAh g −1 after 100 cycles at 2 C charge-discharge rate. In particular, the sulfur-HPHC composite presents a long term cycling stability up to 300 cycles at 1.5 C. The results illustrate that the electrochemical reaction constrained inside the interconnected macro/meso/micropores of HPHC would be the dominant factor for the excellent high rate capability and long cycling stability of the sulfur cathode, and the three-dimensionally honeycomb carbon network would be a promising carbon matrix structure for lithium-sulfur battery cathode.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
CARBON
·
2018
·
IF 7.082
Guang Li,Qingfeng Yi,Xiaokun Yang,Yao Chen,Xiulin Zhou,Gang Xie
Ni-Co-N doped honeycomb carbon (HC) nano-composites Ni 3 Co 1 -N/HC (Ni 3 Co 1 -N/HC-20, Ni 3 Co 1 -N/HC-30 and Ni 3 Co 1 -N/HC-40 with respective metal mass percentage of 20%, 30% and 40%) with a regular hexagonal structure have been fabricated by using the simple polymethylmethacrylate (PMMA) emulsion template method . The side length of the carbon hexagon is ca. 100 nm for the honeycomb carbon (HC). For the Ni 3 Co 1 -N/HC catalysts, the NiCo nanoparticles and the nanocarbon tubes derived from dicyandiamide are uniformly dispersed on HCs. The as-synthesized Ni 3 Co 1 -N/HC catalysts exhibit efficient electroactivity for oxygen reduction reaction (ORR) in alkaline medium and possess excellent tolerance to the alcohols (ethanol, n -propanol and iso -propanol). Based on these results, a membrane-less direct alcohol fuel cell has been assembled with the Ni 3 Co 1 -N/HC as the cathodic catalyst, the ternary Pd 7 Ag 2 Sn 2 /CNT as the anodic catalyst and alcohol (ethanol, n -propanol or iso -propanol) as the fuel. The fuel cell with the Ni 3 Co 1 -N/HC-40 as the cathodic catalyst displays the open circuit voltage of 0.79 V and maximum power density of 42.2 mW cm −2 for the ethanol fuel , 0.60 V and 33.3 mW cm −2 for the n -propanol fuel, and 0.43 V and 14.4 mW cm −2 for the iso -propanol fuel. The membrane-less fuel cell also presents stable discharge performance at different discharging current densities.
研究领域:
材料科学
·
电化学
·
能源技术
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）