Small
·
2023
·Vol. 19
·期 40
·2303227
·
IF 13.3
YuanZhe Wu,Quan Zong,Chaofeng Liu,Yanling Zhuang,Daiwen Tao,Jiangying Wang,Jingji Zhang,Qilong Zhang,Guozhong Cao
Vanadyl phosphate (VOPO 4 ·2H 2 O) has been regarded as one of the most promising cathode materials for aqueous Zn-ion batteries due to its distinct layered structure. However, VOPO 4 ·2H 2 O has not yet demonstrated the exceptional Zn ion storage performance owing to the structural deterioration during repeated charging/discharging process and poor intrinsic conductivity. In this work, 2D sodium vanadyl phosphate (NaVOPO 4 ·0.83H 2 O, denoted as NaVOP) is designed as a cathode material for Zn-ion batteries, in which sodium ions are preinserted into the interlayer, replacing part of water. Benefiting from the in situ surface oxidization, improved electronic conductivity, and increased hydrophobicity, the NaVOP electrode exhibits a high discharge capacity of 187 mAh g −1 at 0.1 A g −1 after activation, excellent rate capability and enhanced cycling performance with 85% capacity retention after 1500 cycles at 1 A g −1 . The energy storage mechanism of the NaVOP nanoflakes based on the rapid Zn 2+ and H + intercalation pseudocapacitance are investigated via multiple ex situ characterizations.
研究领域:
材料科学
·
电化学
·
能源存储
·
无机化学
·
纳米材料
✓ 已验证
DOI
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2017
·
IF 3.012
Haojie Zhu,Ke Yang,Hua Lan,Shangshu Qian,Haoxiang Yu,Lei Yan,Nengbing Long,Miao Shui,Jie Shu
In this work, Na 2 Ti 3 O 7 is fabricated as lithium storage material via one-step solid state reaction. Worked as anode material , Na 2 Ti 3 O 7 delivers a stable electrochemical performance with good lithium storage capability. Structural analyses show that Na 2 Ti 3 O 7 anode experiences slight volume change during electrochemical lithiation/delithiation process. Moreover, the reversibility of structural evolution is further demonstrated by in-situ X-ray diffraction technique . All these evidences prove the cycling stability of Na 2 Ti 3 O 7 as lithium storage material. Besides, the kinetic properties of the Li + ion storage in Na 2 Ti 3 O 7 are systematically investigated. The observed results reveal that Na 2 Ti 3 O 7 delivers the lithium ions diffusion coefficient in the range of 10 − 14 –10 − 12 cm 2 s − 1 during the discharge process and 10 − 15 –10 − 12 cm 2 s − 1 during the recharge process. It suggests that Na 2 Ti 3 O 7 has good lithiation/delithiation kinetics in rechargeable batteries.
研究领域:
电化学
·
材料科学
·
能源存储
·
无机化学
·
固体化学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Bin Qin,Yifei Cai,Xiaoqing Si,Chun Li,Jian Cao,Weidong Fei,Junlei Qi
The practical application of lithium-sulfur (Li-S) batteries is impeded by the shuttle effect of intermediate polysulfides and the inherent sluggish kinetics. Herein, Mo 2 C nanocatalysts anchoring on holey graphene scaffold (Mo 2 C@HGr) is explored as a lightweight and ultrathin modified separator to conquer the above issues. The artificially customized holes on holey graphene sheets facilitate ionic transfer and electrolyte penetration, and further enhance the sulfur utilization under lean electrolyte conditions. The experimental results together with theoretic calculation demonstrate the favourable chemical adsorption ability of Mo 2 C sites that blocking the diffusion of LiPSs. Abundant triple-phase interfaces among Mo 2 C nanomediators, holey graphene and electrolyte boost the conversion kinetics of the intercepted LiPSs. As a result, the cell with Mo 2 C@HGr modified separator shows superior rate capability (836 mAh g −1 ) even at 5 C current with a negligible Mo 2 C@HGr loading of 0.08 mg cm −2 . Furthermore, ultrahigh areal capacity of 5.9 mAh cm −2 is still attained with high sulfur loading of 6 mg cm −2 under lean electrolyte operation (E/S = 5.6 µL mg −1 ). This design concept can be extended to other graphene based multifunctional nanocomposite toward the development of more practical Li-S batteries.
研究领域:
电化学
·
能源材料
·
纳米催化
·
电池技术
·
功能复合材料
✓ 已验证
DOI
高影响因子
COMBUSTION AND FLAME
·
2021
·
IF 4.185
Jizhen Zhu,Sixu Wang,Mohsin Raza,Yuan Feng,Jing Li,Yebing Mao,Liang Yu,Yong Qian,Xingcai Lu
Methanol is an attractive oxygenate increasingly used as primary fuel for dual-fuel combustion technology yielding beneficial thermal-efficiency and emissions in modern engines. As such, it is significant to fundamentally understand the autoignition behavior of methanol/diesel mixtures. This study measured the ignition delay times (IDTs) of methanol/diesel blends with different mixing ratios (30%, 50%, 70% methanol by mol.) on a heated shock tube and a heated rapid compression machine at temperatures of 650−1450 K, pressures of 6−20 bar, and equivalence ratios of 0.5, 1.0 and 2.0. The typical two-stage ignition characteristics with the negative temperature coefficient response were observed for dual-fuel mixtures. In general, both the total and first-stage IDTs decrease with the increment of pressure and equivalence ratio as well as diesel proportion in mixtures. The simulation results performed with a published detailed mechanism in conjunction with a tri-component diesel surrogate demonstrate generally good agreement with the experimental data at all test conditions. Moreover, a crossover of IDTs occurs at a higher temperature (~1500 K) for varying equivalence ratios, and experiment and simulation both exhibit a non-linear mixing effect of methanol addition on diesel ignition. Interestingly, simulation results clearly suggest a crossover (~940 K) for mixtures with varying methanol content at an intermediate-temperature, where the IDT of the mixture with a lower methanol ratio becomes longer as the temperature is higher than that of the crossover. Furthermore, brute-force sensitivity analyses assisted with reaction path analysis were conducted to gain deeper insights into the autoignition chemistry of dual-fuel mixtures, especially for the chemical interaction between both fuels during the low-temperature oxidation process . It is found that methanol hardly generates •OH, whereas •OH is mainly produced by the low-temperature reaction pathways of diesel. Thus, •OH is the bridge for both fuels during the ignition process. At the high methanol ratio, the H-abstraction of diesel is mainly via •HO 2 while CH 3 OH consumes a large percentage of •OH. Consequently, the competition between methanol and diesel for •OH radicals inhibits the overall reactivity of reaction network. In addition, the original data reported here lay a foundation for the development and validation of more accurate and robust dual-fuel kinetic schemes.
研究领域:
燃烧化学
·
燃料科学
·
化学动力学
·
内燃机工程
·
替代燃料技术
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）