Jun Ma

Dr. Jun Ma

orcid

Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
16 June 2022 in Nanomaterials
Verified
Journal Article
Open access
PDF file
AXAihong Xu
Aihong Xu
RWRuoming Wang
Ruoming Wang
MYMengqin Yao
Mengqin Yao
JCJianxin Cao
Jianxin Cao
MLMengjun Li
Mengjun Li
JMJun Ma
Jun Ma
An Li1.3Al0.3SnxTi1.7−x(PO4)3 (LATP-xSn) ceramic solid electrolyte was prepared by Sn doping via a solid phase method. The results showed that adding an Sn dopant with a larger ionic radius in a concentration of x = 0.35 enabled one to equivalently substitute Ti sites in the LATP crystal structure to the maximum extent. The uniform Sn doping could produce a stable LATP structure with small grain size and improved relative density. The lattice distortion induced by Sn doping also modified the transport channels of Li ions, which promoted the increase of ionic conductivity from 5.05 × 10−5 to 4.71 × 10−4 S/cm at room temperature. The SPE/LATP-0.35Sn/SPE composite solid electrolyte with a sandwich structure was prepared by coating, which had a high ionic conductivity of 5.9 × 10−5 S/cm at room temperature, a wide electrochemical window of 4.66 V vs. Li/Li+, and a good lithium-ion migration number of 0.38. The Li||Li symmetric battery test results revealed that the composite solid electrolyte could stably perform for 500 h at 60 °C under the current density of 0.2 mA/cm2, indicating its good interface stability with metallic lithium. Moreover, the analysis of the all-solid-state LiFePO4||SPE/LATP-0.35Sn/SPE||Li battery showed that the composite solid electrolyte had good cycling stability and rate performance. Under the conditions of 60 °C and 0.2 C, stable accumulation up to 200 cycles was achieved at a capacity retention ratio of 90.5% and a coulombic efficiency of about 100% after cycling test.


5 January 2025 in Chemistry – A European Journal
Verified
Journal Article
Closed access
HSHanjie Si
Hanjie Si
JMJun Ma
Jun Ma
XXXiao Xia
Xiao Xia
QWQingmei Wang
Qingmei Wang
SGShuo Geng
Shuo Geng
LFLin Fu
Lin Fu

Verified
Journal Article
Open access
PDF file
XXXiao Xia
Xiao Xia
JMJun Ma
Jun Ma
Shuo GengShuo Geng
Shuo Geng
FLFei Liu
Fei Liu
MYMengqin Yao
Mengqin Yao
Unconventional heavy oil ores (UHO) have been considered an important part of petroleum resources and an alternative source of chemicals and energy supply. Due to the participation of water and extractants, oil–solid separation (OSS) and oil–water separation (OWS) processes are inevitable in the industrial separation processes of UHO. Therefore, this critical review systematically reviews the basic theories of OSS and OWS, including solid wettability, contact angle, oil–solid interactions, structural characteristics of natural surfactants and interface characteristics of interfacially active asphaltene film. With the basic theories in mind, the corresponding OSS and OWS mechanisms are discussed. Finally, the present challenges and future research considerations are touched on to provide insights and theoretical fundamentals for OSS and OWS. Additionally, this critical review might even be useful for the provision of a framework of research prospects to guide future research directions in laboratories and industries that focus on the OSS and OWS processes in this important heavy oil production field.

Verified
Journal Article
Open access
PDF file
XXXiao Xia
Xiao Xia
JMJun Ma
Jun Ma
FLFei Liu
Fei Liu
HCHaifeng Cong
Haifeng Cong
XLXingang Li
Xingang Li
In the heavy petroleum industry, the development of efficient demulsifiers for the effective breaking of interfacially active asphaltenes (IAA)-stabilized water-in-heavy oil (W/HO) emulsions is a highly attractive but challenging goal. Herein, a novel nitrogen and oxygen containing demulsifier (JXGZ) with strong hydrogen bonding has been successfully synthesized through combining esterification, polymerization and amidation. Bottle tests indicated that JXGZ is effectual in quickly demulsifying the IAA-stabilized W/HO emulsions; complete dehydration (100%) to the emulsions could be achieved in 4 min at 55 °C using 400 ppm of JXGZ. In addition, the effects of demulsifier concentration, temperature and time on the demulsification performance of JXGZ are systematically analyzed. Demulsification mechanisms reveal that the excellent demulsification performance of JXGZ is attributed to the strong hydrogen bonding between JXGZ and water molecules (dual swords synergistic effect under hydrogen bond reconstruction). The interaction of the “dual swords synergistic effect” generated by two types of hydrogen bonds can quickly break the non-covalent interaction force (π-π stacking, Van der Waals force, hydrogen bonds) of IAA at the heavy oil–water interface, quickly promote the aggregation and coalescence of water molecules and finally achieve the demulsification of W/HO emulsions. These findings indicate that the JXGZ demulsifier shows engineering application prospects in the demulsification of heavy oil–water emulsions, and this work provides the key information for developing more efficient chemical demulsifiers suitable for large-scale industrial applications.

3 September 2023 in Electrochimica Acta
Verified
Journal Article
Closed access
QWQingyang Wang
Qingyang Wang
AYAnjie Yang
Anjie Yang
JMJun Ma
Jun Ma
MYMengqin Yao
Mengqin Yao
SGShuo Geng
Shuo Geng
FLFei Liu
Fei Liu