Non-Flammable Electrolytes for High Performance Batteries

In all battery systems, the electrolyte plays a vital role in determining the stability of the electrodes, as well as the safety of the battery users. Due to the frequently reported thermal runaway accidents in batteries, the key criteria for selecting the electrode materials for industrial production purposes must focus not only on providing high energy density, but also on their long-term stability and the safety of consumers. The potassium ion battery (PIB) has received much attention in battery research due to large earth abundance of potassium resources and its similar properties to lithium (LIBs) and sodium ion batteries (SIBs). It should be noted that the PIB has great potential to work at higher voltages and provides a higher energy density, because of the lower redox potential of K+ than Na+. Another important motivation for PIB research as opposed to SIB is the reversible intercalation of K atoms into graphite, as a high theoretical capacity of 279 mAh/g was discovered based on the generated compound KC8, demonstrating an encouraging prospect for commercialization of PIBs

An In-Depth Study of Zn Metal Surface Chemistry for Advanced Aqueous Zn-Ion Batteries

© 2020 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim Although Zn metal has been regarded as the most promising anode for aqueous batteries, it persistently suffers from serious side reactions and dendrite growth in mild electrolyte. Spontaneous Zn corrosion and hydrogen evolution damage the shelf life and calendar life of Zn-based batteries, severely affecting their industrial applications. Herein, a robust and homogeneous ZnS interphase is built in situ on the Zn surface by a vapor–solid strategy to enhance Zn reversibility. The thickness of the ZnS film is controlled via the treatment temperature, and the performance of the protected Zn electrode is optimized. The dense ZnS artificial layer obtained at 350 °C not only suppresses Zn corrosion by forming a physical barrier on the Zn surface, but also inhibits dendrite growth via guiding the Zn plating/stripping underneath the artificial layer. Accordingly, a side reaction-free and dendrite-free Zn electrode is developed, the effectiveness of which is also convincing in a MnO2/ZnS@Zn full-cell with 87.6% capacity retention after 2500 cycles

From room temperature to harsh temperature applications: Fundamentals and perspectives on electrolytes in zinc metal batteries

As one of the most competitive candidates for the next-generation energy storage systems, the emerging rechargeable zinc metal battery (ZMB) is inevitably influenced by beyond-room-temperature conditions, resulting in inferior performances. Although much attention has been paid to evaluating the performance of ZMBs under extreme temperatures in recent years, most academic electrolyte research has not provided adequate information about physical properties or practical testing protocols of their electrolytes, making it difficult to assess their true performance. The growing interest in ZMBs is calling for in-depth research on electrolyte behavior under harsh practical conditions, which has not been systematically reviewed yet. Hence, in this review, we first showcase the fundamentals behind the failure of ZMBs in terms of temperature influence and then present a comprehensive understanding of the current electrolyte strategies to improve battery performance at harsh temperatures. Last, we offer perspectives on the advance of ZMB electrolytes toward industrial application

Design of electrolyte for boosted aqueous battery performance: A critical review and perspective

Aqueous alkali and multivalent metal-ion batteries are practically advantageous for large-scale energy storage because of intrinsic safety and environmental friendliness. Drawbacks, however, include low energy density and short life because of limited electrochemical stability windows (ESWs) of aqueous electrolytes and rapid degradation of electrode materials with high water activity. Despite significant research, including water-in-salt and electrolyte additive(s), directed to the electrolyte to extend ESWs and to boost electrode stability, the practical application remains limited because of the present high cost and generally unsatisfactory performance. Although alkali and multivalent metal ions can have different coordinating structures with solvents and anions, electrolyte design strategies share fundamental mechanisms in either extending ESWs or achieving a passivation layer on the electrode material(s). Future development of aqueous batteries, therefore, is dependent on a systematic understanding and analysis of electrolyte research. Here, we report for the first time a systematic review of the design and engineering of emerging water-based electrolytes for boosted aqueous rechargeable batteries (ARBs) performance. We present a comparative summary of electrochemical stability windows and electrode/electrolyte interphases for five (5) electrolyte types; appraise strategies and the resulting impact of electrolyte properties on electrode interfacial stability; analyze in situ generated electrode/electrolyte interphases; classify advantages and drawbacks of selected strategies; and provide a perspective on future developments in aqueous alkali and multivalent metal-ion batteries, together with methods for the study of both electrolyte and derived interphase(s). We conclude that (1) the design of electrolytes of high concentration and hybrid and eutectic solvents are practically promising for high energy density ARBs; (2) there is a need to improve design for longer cycling life of ARBs; (3) research addresses boosting ESW of the electrolyte; and (4) it increased the understanding of the electrode/electrolyte interface stability via new electrode/electrolyte interphase structures. This review will be of benefit in the practical design of electrolyte(s) for aqueous batteries for high performance and, therefore, of interest to researchers and manufacturers

Regulating the reduction reaction pathways via manipulating the solvation shell and donor number of the solvent in Li-CO2 chemistry

Transforming CO2 into valuable chemicals is an inevitable trend in our current society. Among the viable end-uses of CO2, fixing CO2 as carbon or carbonates via Li-CO2 chemistry could be an efficient approach, and promising achievements have been obtained in catalyst design in the past. Even so, the critical role of anions/solvents in the formation of a robust solid electrolyte interphase (SEI) layer on cathodes and the solvation structure have never been investigated. Herein, lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) in two common solvents with various donor numbers (DN) have been introduced as ideal examples. The results indicate that the cells in dimethyl sulfoxide (DMSO)-based electrolytes with high DN possess a low proportion of solvent-separated ion pairs and contact ion pairs in electrolyte configuration, which are responsible for fast ion diffusion, high ionic conductivity, and small polarization. The 3 M DMSO cell delivered the lowest polarization of 1.3 V compared to all the tetraethylene glycol dimethyl ether (TEGDME)-based cells (about 1.7 V). In addition, the coordination of the O in the TFSI- anion to the central solvated Li+ ion was located at around 2 Å in the concentrated DMSO-based electrolytes, indicating that TFSI- anions could access the primary solvation sheath to form an LiF-rich SEI layer. This deeper understanding of the electrolyte solvent property for SEI formation and buried interface side reactions provides beneficial clues for future Li-CO2 battery development and electrolyte design

MOFs-derived core-shell Co3Fe7@Fe2N nanopaticles supported on rGO as high-performance bifunctional electrocatalyst for oxygen reduction and oxygen evolution reactions

© 2020 Elsevier Ltd Exploring stable and highly efficient bifunctional electrocatalysts for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is critical for the novel energy conversion and storage devices including fuel cells and metal-air batteries. Herein, the core-shell structured Co3Fe7@Fe2N nanoparticles supported on reduced graphene oxide (rGO) nanosheets (Co3Fe7@Fe2N/rGO) is designed though the simple annealing of MOFs. The as-fabricated samples present an excellent electrocatalytic performance for ORR and OER due to the synergistic effect of electrode materials. The Co3Fe7@Fe2N/rGO exhibits an onset potential of 0.98 V (vs. Reversible hydrogen electrode), peak current intensity of 1.531 A g−1 and long-term stability for ORR, which is close to that of the benchmark Pt/C (20%) in 0.1 M KOH. It also shows good oxygen evolution reaction (OER) performance with an overpotential of 371 mV (at 10 mA cm−2). When used as a bifunctional air electrode in Zn-air batteries, the core-shell materials enabled an excellent mass power density of 60 W cm−2 g−1 at 0.57 V and stable cycling performance for over 100 cycles

Bio-inspired design of an in situ multifunctional polymeric solid-electrolyte interphase for Zn metal anode cycling at 30 mA cm\u3csup\u3e-2\u3c/sup\u3eand 30 mA h cm\u3csup\u3e-2\u3c/sup\u3e

A solid-electrolyte interphase (SEI) is highly desirable to restrain Zn dendrite growth and side reactions between a Zn anode and water in rechargeable aqueous zinc-ion batteries (RAZBs), but remains a challenge. Here, inspired by the bio-adhesion principle, a stable SEI of polydopamine is constructed successfully on a Zn anode via an in situ electrochemical polymerization process of a dopamine additive. This in situ polymeric SEI offers multifunctional features with abundant functional groups and outstanding hydrophilicity for regulating Zn nucleation to achieve dendrite-free Zn deposition, high Zn-ion conductivity for fast Zn2+ transport, and strong adhesion capability for blocking interfacial side reactions. Consequently, the Zn electrodes exhibited high reversibility with 99.5% coulombic efficiency and outstanding stability, even at ultrahigh current density and areal capacity (30 mA cm-2 and 30 mA h cm-2). Moreover, a prolonged lifespan can be attained for the Zn/V2O5 full cell in a lean electrolyte (9 μL mA h-1) and with a low capacity ratio of the negative electrode to the positive electrode (∼2). This work provides inspiration for the design of SEI layers in aqueous battery chemistry and promotes the practical application of RAZBs

A CoSe-C@C core-shell structure with stable potassium storage performance realized by an effective solid electrolyte interphase layer

Conversion/alloying materials with high theoretical capacity are promising for potassium-ion batteries, although their development is seriously blocked owing to their volume expansion and ineffective solid-electrolyte interphase (SEI) protection. Herein, it is discovered that the performance of the CoSe anode material could be enhanced through a flexibly designed core-shell structure (denoted as CoSe-C@C) and an inorganic compound-rich SEI. The CoSe-C@C electrode exhibits stable cycling performance (432 mA h g-1 at 200 mA g-1) over 1000 cycles and outstanding rate capability (233 mA h g-1 at 10 A g-1). A reversible conversion mechanism for the potassiation/depotassiation in CoSe is revealed by ex situ X-ray diffraction patterns and high-resolution transmission electron microscope images, while the SEI on the CoSe-C@C surface is found to be inorganic-rich (KF-), which is favourable for K ion diffusion and charge transfer dynamics. These findings would shed light on nanostructure design strategies and our fundamental understanding of the SEI formation in electrolyte engineering for potassium-ion batteries. This journal i

MOR promotes epithelial-mesenchymal transition and proliferation via PI3K/AKT signaling pathway in human colorectal cancer

The mu-opioid receptor (MOR), a membrane-bound G protein-coupled receptor, is implicated in progression and long-term outcome of several types of tumors. However, the expression and clinical significance of MOR in colorectal cancer (CRC) remain unclear. In this study, a total of 180 paraffin-embedded samples of paired tumors and normal tissues from CRC patients are used to explore expression levels of MOR by immunohistochemistry (IHC). Results show that MOR is highly expressed in tumors compared with that in paired normal tissues ( P<0.0001). MOR expression levels are associated with the degree of differentiation ( P<0.001) and the regional lymph node metastasis ( P<0.001). In addition, a significant difference is also found in the overall survival (OS) between MOR low- and high-expression groups ( P=0.002), especially in patients with TNM stage III or IV CRC ( P=0.007). Both univariate ( P=0.002) and multivariate ( P=0.013) analyses indicated that MOR is an independent risk factor associated with CRC prognosis. We further investigate the mechanism in MOR-positive CRC cell line HCT116. The results show that silencing of MOR significantly suppresses epithelial-mesenchymal transition (EMT), in addition to suppressing cell proliferation, migration, and invasion. In addition, the expression of downstream p-AKT is also significantly downregulated, and the above suppression effect could be rescued by PI3K/AKT signaling agonist. We conclude that MOR mediates EMT via PI3K/AKT signaling, facilitating lymph node metastasis and resulting in poor survival of CRC patients. Our findings suggest that MOR is a novel prognostic indicator and the application of opioid receptor antagonists may be a novel therapeutic strategy for CRC patients with high MOR expression