查找使用阿拉丁产品的科研文献

Interfacial Reconstruction Toward Reversible Mg Anode in Conventional Electrolytes

Caiyun Wang,Huiqin Huang,Xingxing Wu,Muhammad Yousaf,Mi Yan,Yinzhu Jiang

Rechargeable magnesium batteries are considered with great potential as sustainable, economic-friendly, safe energy storage techniques. Whereas, the Mg metal anode exhibits limited plating/stripping behavior in the conventional electrolytes due to the severe passivation. Herein, a facile LiI solution treatment is reported to reconstruct the interphase between Mg metal anode and electrolytes, converting the original passivation film to I-riched solid electrolyte interphase with the ability of rapid Mg2+ migration, which can reduce the overpotential for Mg anode plating/stripping from 2 to 0.4 V at 0.1 mA cm–2. In addition, Li+ from the LiI precursor can be released and shuttles to the Mo6S8 cathode side, promoting cointercalation of Mg2+. With the simultaneous improvement of the anode and cathode, the Mg//Mo6S8 full cell delivers a decreasing voltage hysteresis (0.1 V) and much enhanced specific capacity (80.8 mAh g–1). This work provides a maneuverable anode treatment for constructing a passivation-against interphase between Mg metal anode and the conventional electrolytes, contributing an insight for the development toward high-performance Mg batteries.

Mg-doped layered oxide cathode for Na-ion batteries

Yuejun Ding,Feixiang Ding,Xiaohui Rong,Yaxiang Lu,Yong-Sheng Hu

Na-ion batteries (NIBs) are regarding as the optimum complement for Li-ion batteries along with the rapid development of stationary energy storage systems. In order to meet the commercial demands of cathodes for NIBs, O3-type Cu containing layered oxide Na0.90Cu0.22Fe0.30Mn0.48O2 with good comprehensive performance and low-cost element components is very promising for the practical use. However, only part of the Cu3+/Cu2+ redox couple participated in the redox reaction, thus impairing the specific capacity of the cathode materials. Herein, Mg2+-doped O3-Na0.90Mg0.08Cu0.22Fe0.30Mn0.40O2 layered oxide without Mn3+ was synthesized successfully, which exhibited improved reversible specific capacity of 118 mAh/g in the voltage range of 2.4–4.0 V at 0.2 C, corresponding to the intercalation/deintercalation of 0.47 Na+ (0.1 more than that of Na0.90Cu0.22Fe0.30Mn0.48O2). This work demonstrates an important strategy to obtain advanced layered oxide cathodes for NIBs.

Reversing Mg suppression effect on Co-site water oxidation of MgCo2O4 based on vanadium-atom electronic affinity synergy with Mg sites toward electronic redistribution

Hui Zhang,Hui Han,Xuan Yang,Hongyu Ma,Zhifei Song,Xuqiang Ji

Active-site regeneration from d-band-center control engineering and electronic redistribution based on target-atom implantation is of enormous importance for efficient water oxidation. Here, low-activity Co catalytic sites of MgCo2O4 are reactivated for large-current (500 mA cm−2) and high-efficiency water oxidation through vanadium-atom electronic affinity synergy with Mg sites toward charge rearrangement around Co sites. Interestingly, very little vanadium (1.3 wt%) was implanted into MgCo2O4 to achieve atom-scale structure tailoring and electronic redistribution, reversing the Mg suppression effect on Co-site water oxidation of MgCo2O4. Vanadium-implantation-tailored MgCo2O4 coupled with MgO (V–MgCo2O4@MgO) exhibits significantly enhanced oxygen evolution reaction performance, with low overpotentials of 240 and 290 mV for 100 and 500 mA cm−2, respectively, in 1 M KOH. Operating at 500 mA cm−2, V–MgCo2O4@MgO has good catalytic stability for at least 20 hours. This work constructs excellent catalysts through atomic-level structural regulation and provides a new perspective for the principle of electronic-affinity synergy between V and Mg species toward Co–O bond optimization.

Superhydrophobic and Self-Healing Mg-Al Layered Double Hydroxide/Silane Composite Coatings on the Mg Alloy Surface with a Long-Term Anti-corrosion Lifetime

Ying Wang,Xingyi Zhou,Minhao Yin,Jibin Pu,Ningyi Yuan,Jianning Ding

Both a superhydrophobic structure and layered double hydroxide (LDH) coating were effective to improve the corrosion resistance of alloys. In this study, a superhydrophobic composite coating based on LDHs was constructed on Mg alloy by laser treatment, in situ growth of Mg-Al LDHs, and modification with octadecyl-trimethoxy-silane (OTS). The so-obtained composite coating was coded as L-LDHs-OTS, where L stands for laser treatment. Results showed that the L-LDHs-OTS composite coating presented the best anti-corrosion performance and the corrosion current density was reduced by about 5 orders of magnitude compared with that of the Mg alloy substrate. The excellent corrosion resistance was related to the superhydrophobicity of the composite coating, the compactness and ion-exchange capacity of the LDH layer, and the dense Si-O-Si network within the OTS layer. Moreover, the L-LDHs-OTS composite coating was still effective after 20 days of immersion tests, showing good long-term corrosion resistance due to the existence of hydrophobicity of the composite coating and the self-healing ability of LDHs.

Comment on “Oxygen-Vacancy-Induced Midgap States Responsible for the Fluorescence and the Long-Lasting Phosphorescence of the Inverse Spinel Mg(Mg,Sn)O4”

Litian Lin

Improving Li+/Mg2+ separating performance of polyethylene/polyamide membranes under high Mg(II)/Li(I) ratios: Reverse interface polymerization modulation and Mg(II)-Cyclen interaction

Yangxiang Huang,Mengyao Chen,Lixin Xue,Hangqing Xue,Juexin Wang,Fei Huang,Congjie Gao

To simultaneously increase the Mg 2+ /Li + separating performance under high Mg 2+ /Li + ratios of polyethylene/polyamide (PE/PA) thin film composite (TFC) nanofiltration (NF) membranes, 1,4,7,10-tetraazacyclododecane (Cyclen) was added in the aqueous phase with polyethyleneimine (PEI) monomer. During reverse interface polymerization (RIP) on polyethylene (PE) substrates, phthaloyl chloride (PC) was added to the organic phase with terephthaloyl chloride (TPC) monomer. It was found that the addition of Cyclen and/or PC could both increase the hydrophilicity, surface roughness and average pore sizes of formed virgin PE/PA TFC NF membranes, leading to increased water permeability. The Li + /Mg 2+ separating factor S Li/Mg first increased and then decreased with maximum points at the TPC/PC ratio of 5:1 and Cyclen addition level of 0.02 wt%. Cation absorption, especially Mg(II)-Cyclen interactions in the PA layers under higher Mg 2+ /Li + ratio led to increased surface Zeta potential, decreased average pore diameters μ p, and greatly increased Li + /Mg 2+ separating factor (S Li/Mg ). S Li/Mg value of PEI-TPC/PC 5:1 -Cyclen 0.02 membranes could be increased from 5.0 to 55.47, keeping the water permeability around 6.5 L m −2  h −1  bar −1 when Mg 2+ /Li + ratio increased from 1 to 100 in the brine.

Enhance Mg-based heat storage materials kinetics by complex oxides

Daifeng Wu,Rui Li,Tai Sun,Renheng Tang,Fangming Xiao

Mg/MgH 2 as a thermochemical energy storage (TCES) material suffers from a slow hydrogenation-dehydrogenation kinetic and poor reversibility. Addition of metal oxide is an effective way to improve the kinetic properties of Mg/MgH 2 . However, there is little study on the effects of complex oxides . Thus, the catalytic effects of complex metal oxides and its catalytic mechanism were investigated in this paper. Results show that the dehydrogenation peak temperature and apparent activation energy of MgH 2 -Ta 2 O 5 are 320.8 °C and 128.54 kJ/mol. Combined with complex metal oxide, MgH 2 -Ta 2 O 5 -Nd 2 O 3 could further reduce the dehydrogenation peak temperature (307.2 °C) and apparent activation energy (95.33 kJ/mol). MgO and NdH 2.61 are found in the dehydrogenated MgH 2 -Ta 2 O 5 -Nd 2 O 3 , indicating that n-typed oxide Ta 2 O 5 and p-typed oxide Nd 2 O 3 are formed and improved the kinetics properties of MgH 2 . Furthermore, Nd 2 O 3 /Ta 2 O 5 interface is formed and acted as “p-n junction”. When heating, the “p-n junction” is exposed to thermal radiation and produce electrons and holes, and then the kinetics properties of MgH 2 are further enhanced.

Superhydrophobic composite coating for reliable corrosion protection of Mg alloy

Shijie Song,Han Yan,Meng Cai,Yu Huang,Xiaoqiang Fan,Xuejun Cui,Minhao Zhu

Endowing Mg alloy surface with superhydrophobicity solves its poor corrosion resistance for broadening the wide application fields. However, the superhydrophobicity is vulnerable to failure under service environments due to the exfoliation and degradation of surface material. Hence, a bilayer composite coating composed of microarc oxidation layer and superhydrophobic layer was fabricated to protect Mg alloys by modulating superhydrophobic coating/substrate interface. The bilayer coating with a water contact angle of 158.3° possesses excellent water-repellent, and self-cleaning properties. In addition, the bilayer coating consistently remains superhydrophobicity in acid, alkaline, high/low temperature, and ultraviolet radiation environments, indicating the excellent environmental stability. Notedly, the lowest-frequency impedance value of bilayer coating (6.78 × 10 6 Ω·cm) increases five orders of magnitude compared with that of Mg alloy (60.2 Ω·cm), and the inhibition efficiency is calculated to be 99.99 %. The excellent corrosion resistance of coating is attributed to the synergistic barrier protection of microarc oxidation layer and superhydrophobic layer, implying that it provides effective protection for Mg alloy. Therefore, the as-prepared bilayer coating has great application prospects in corrosion protection of Mg alloys toward different service environments.

Fabrication of Ag containing antibacterial PEO coatings on pure Mg

Qi Han,Yan Li,Xiaopeng Lu,Di Mei,Qianqian Chen,Tao Zhang,Fuhui Wang

Antibacterial plasma electrolytic oxidation (PEO) coatings have been fabricated by in-situ incorporation of Ag particles on pure Mg. It was found that the Ag particles have been partly oxidized and incorporated into the layer during coating formation process. Ag containing PEO coatings can strongly inhibit the growth of S. aureus and the antibacterial efficiency of the coatings is mainly associated with the Ag concentration in the layer. The antibacterial rate of the coating reaches 99% and is maintained to be stable when sufficient Ag particles (above 1 wt%) are incorporated into the layer.

Realizing facile regeneration of spent NaBH4 with Mg–Al alloy

Hao Zhong,Liuzhang Ouyang,Meiqin Zeng,Jiangwen Liu,Hui Wang,Huaiyu Shao,Michael Felderhoff,Min Zhu

The regeneration of sodium borohydride (NaBH4) is crucial to form a closed cycle after it either supplies hydrogen energy via a hydrolysis process or provides energy through electron transfer at the anode of direct borohydride fuel cells (DBFCs). In both of these cases, the spent fuels are NaB(OH)4 from NaBO2 aqueous solution. However, the current regeneration process from (NaB(OH)4)·xH2O to form NaBH4 by reduction reaction and calcination at high temperature with metal hydrides as reducing agents is very expensive. In this work, we developed a simple regeneration process via ball milling with Mg–Al alloys as the reducing agent for NaB(OH)4 under an argon atmosphere. Under optimized conditions, a high yield of about 72% of NaBH4 could be obtained. Mechanistic study showed that all the hydrogen atoms from NaB(OH)4 remain in NaBH4 and no additional hydrogen sources are needed for the reduction process. The inexpensive Mg–Al alloy works as a reducing agent transforming the H+ to H− in NaBH4. This approach demonstrates a ∼20-fold cost reduction compared with the method using metal hydrides. This opens the door to the commercial implementation of simple ball milling processes for the regeneration of spent NaBH4 from NaB(OH)4 with cheap reducing agents.

Highly selective lithium recovery from high Mg/Li ratio brines

Gui Liu,Zhongwei Zhao,Lihua He

Here, we report a new liquid-membrane electrodialysis capable of selectively recovering lithium from high Mg/Li ratio brines. The liquid membrane is composed of an ionic liquid system as the Li + carrier that presents high selectivity toward Li + and long-term sustainability, and 2 solid cation-exchange membranes to sandwich the carrier. Recognition and selective electromigration of Li + can be achieved by the sandwiched liquid membrane assisted by an electric field. The Mg/Li decreases from 50:1 in the initial feeding brine to 0.5:1 in the receiving solution after electrodialysis at a current density of 4.375 A·m − 2 for 12 h. Moreover, higher current efficiency (65%) and lower specific energy consumption (16 Wh·g − 1 Li) are obtained compared to typical electrodialysis processes. From the perspective of practical application, the Mg/Li drops to 0.26:1 from 53:1 in the old brine from West Taijinair, and K + and Ca 2+ in the brine are almost completely blocked by the liquid membrane. This method displays a great perspective on the application for lithium recovery from high Mg/Li brines owing to its high selectivity, efficient energy utilization, and environmental friendliness.

Powder metallurgical low-modulus Ti–Mg alloys for biomedical applications

Yong Liu,Kaiyang Li,Tao Luo,Min Song,Hong Wu,Jian Xiao,Yanni Tan,Ming Cheng,Bing Chen,Xinrui Niu,Rong Hu,Xiaohui Li,Huiping Tang

In this work, powder metallurgical (PM) Ti–Mg alloys were prepared using combined techniques of mechanical alloying and spark plasma sintering. The alloys mainly consist of super saturations of Mg in Ti matrix, and some laminar structured Ti- and Mg-rich phases. The PM Ti–Mg alloys contain a homogeneous mixtures of nanocrystalline Mg and Ti phases. The novel microstructures result in unconventional mechanical and biological properties. It has been shown that the PM Ti–Mg alloys have a much lower compression modulus (36–50   GPa) compared to other Ti alloys, but still remain a very high compressive strength (1500–1800   MPa). In addition, the PM Ti–Mg alloys show good biocompatibility and bioactivity. Mg can dissolve in the simulated body fluids, and induce the formation of the calcium phosphate layer. The compression modulus of PM Ti–Mg alloys decreases with the amount of Mg, while the bioactivity increases. Although the corrosion resistance of Ti–Mg alloys decreases with the content of Mg, the alloys still show good stability in simulated body fluid under electrochemical conditions. The indirect and direct cytotoxicity results show that PM Ti–Mg alloys have a good biocompatibility to NIH-3T3 cells. Therefore, the PM Ti–Mg alloys are promising candidates in biomedical applications.