| 1. |
- Liu, Yanyan, et al.
(author)
-
Single-phase electronic-ionic conducting Sm3+/Pr3+/Nd3+ triple-doped ceria for new generation fuel cell technology
- 2018
-
In: International journal of hydrogen energy. - : Elsevier. - 0360-3199 .- 1879-3487. ; 43:28, s. 12817-12824
-
Journal article (peer-reviewed)abstract
- Co-doped CeO2 materials have exhibited promising potential for low temperature solid oxide fuel cell (LT-SOFC) applications. Sm3+, Pr3+ and Nd3+ triple-doped ceria has been synthesized via two-step wet chemical approach. First samarium doped ceria (SDC) was prepared and then the Pr3+/Nd3+ ions as doping elements (secondary process) was added. The structural structure was studied by X-ray diffraction (XRD), that indicate Sm3+, Prat and Nd3+ ions are doped into the ceria lattice up to the certain limit (Pr3+/Nd3+ 10 wt%). The impurity peaks are detected as doping contents increased above the certain limit (Pr3+/Nd3+ 20 wt %). In this work, further we investigated the effect increasing Pr3+/Nd3+ doping concentration on the performance of SOFC device. Here, we studied that high-concentration triple-doped ceria samples with mixed electrons/ions conductive property, as the semiconductor-ionic conducting layer, combined with commercial p-type semiconductor Ni0.8Co0.15Al0.05LiO2-delta (NCAL) to fabricate the 'sandwich' configuration for a developing fuel cell technology-electrolyte free fuel cells (EFFCs). This button size fuel cell delivered a maximum power output of 1011 mW cm(-2). The demonstrated findings show that the single-phase semiconductor-ionic material-Sm3+/Pr3+/Nd3+ triple-doped CeO2 can be selected potential candidate for the further development the EFFC technology.
|
|
| 2. |
- Liu, Xueqi, et al.
(author)
-
Study on charge transportation in the layer-structured oxide composite of SOFCs
- 2018
-
In: International journal of hydrogen energy. - : Elsevier. - 0360-3199 .- 1879-3487. ; 43:28, s. 12773-12781
-
Journal article (peer-reviewed)abstract
- In the past few years, triple (H+/O2-/e(-)) conducting materials have been regarded as one of the most promising electrode categories for solid oxide fuel cells (SOFCs). In this work, a layer-structured LiNi0.8Co0.15Al0.05O2-delta (LNCA) with triple conduction has been studied. The semiconductor-ionic conductor (SIC) LNCA-SDC composite has been fabricated by compositing the LNCA material with ionic conductor, i.e., samarium doped ceria (SDC). The electrochemical performance of the LNCA-SDC composite was studied by electrochemical impedance spectroscopy, while its electronic conductivity was confirmed by d.c. polarization method. It is found that the ionic conductivity of the composite is higher than the electronic conductivity by several orders of magnitude. The charge carriers and transportation properties of LNCA-SDC were studied using H+ and O2- blocking layer cells respectively. Results prove that the LNCA-SDC composite is a hybrid oxygen ion-proton conducting material. The oxygen ion conduction is dominated at low temperature (425 -500 degrees C), however, it is comparable with H+ conduction at high temperature (550 degrees C). Additionally, the formation of Li2CO3 under fuel cell operation environment was observed and the mechanism of the hybrid conductivity of LNCA-SDC was studied.
|
|
| 3. |
- Xia, Chen, et al.
(author)
-
Semiconductor electrolyte for low-operating-temperature solid oxide fuel cell : Li-doped ZnO
- 2018
-
In: International journal of hydrogen energy. - : Elsevier. - 0360-3199 .- 1879-3487. ; 43:28, s. 12825-12834
-
Journal article (peer-reviewed)abstract
- Semiconductors have been successfully demonstrated as the electrolytes for solid oxide fuel cells (SOFCs) in recent years. Many such semiconductors have shown their potentials as a competent ionic conductor for fuel cell operation, indicated by the appreciable ionic conduction and electrochemical performance. In the present study, we depart from traditional electrolyte concept to introduce a new semiconductor electrolyte, Li-doped ZnO to low-operating-temperature SOFCs. The used material was synthesized via a co-precipitation method and investigated from phase structure, morphology and UV-vis absorption perspectives. Utilizing Li-doped ZnO as electrolyte layer, we found the corresponding fuel cell exhibited a remarkable maximum power density of 443 mW cm(-2) along with open circuit voltage (OCV) of 1.07 V at 550 degrees C, and represented a lower-temperature operation feasibility with power outputs of 138-165 mW cm(-2) at 425-450 degrees C. Besides, high ionic conductivities of 0.028-0.087 S cm(-1) and low activation energy of 0.5 eV were also found in the synthesized Li-doped ZnO at 425-550 degrees C. Our investigation in terms of electrochemical impedance spectra (EIS) analysis manifested that Li-doped ZnO as the electrolyte layer boosted the electrode reactions of the device, which resulted in rather small polarization resistances and eventually realized good low-temperature performances. Further study based on the rectification characteristic of Ni/Li-doped ZnO contact verified the Schottky junction formation of Li-doped ZnO with anodic Ni, which can avoid the underlying electronic short-circuiting problem. These findings show a profound significance of using doped semiconductor for the future exploitation of SOFC electrolytes.
|
|
| 4. |
- Zhou, Hong, et al.
(author)
-
Relationship between moderate to late preterm, diet types and developmental delay in less-developed rural China.
- 2022
-
In: Nutritional neuroscience. - : Informa UK Limited. - 1476-8305 .- 1028-415X. ; 25:1, s. 70-79
-
Research review (peer-reviewed)abstract
- Aim: To measure the development of moderate to late preterm children by Ages and Stages Questionnaires (ASQ) and explore the relationship between moderate to late preterm, diet types and development delay in less-developed rural China.Methods: Data were collected from a cross-sectional community-based survey, which recruited 1748 children aged 1-59 months in eight counties of China. Caregivers of these children completed the Chinese version of ASQ-3 (ASQ-C) while physical examination and questionnaires on socio-demographic characteristics were conducted. Multivariate logistic regressions were used to analyze the association between moderate to late preterm and suspected developmental delay, as well as the association between diet types and suspected developmental delay. Consumption of certain food types was compared between moderate to late preterm and full-term children.Results: The prevalence of suspected overall developmental delay was 31.3% in the moderate to the late preterm group, compared with 21.6% in the full-term group. Moderate to late preterm birth was not associated with total suspected developmental delay and developmental delay in all the domains of ASQ, except for fine motor (OR = 2.43 95% C.I.: 1.04-5.56). The intake of vegetables and fruits had a protective influence on developmental delay in fine motor function, and moderate to late preterm children had lower relative consumption of fruits and vegetables than full-term children.Conclusion: Moderate to late preterm children in rural China showed an increased likelihood of developmental delay in fine motor function. Future interventions to improve the intake of vegetables and fruits in moderate to late preterm children are recommended.
|
|
