Voltage plateau during relaxation or discharge after charging is a distinct signal associated with stripping of deposited Li metal and hence a feasible tool for online detection of Li plating in ...Li-ion batteries. Here, we present a physics-based model with incorporation of Li plating and stripping to gain a fundamental understanding of the voltage plateau behavior. Specifically, we focus on the internal cell characteristics when voltage plateau occurs and on key factors affecting the shape and duration of voltage plateau. Furthermore, the validity of using the duration of voltage plateau for estimating Li plating amount is assessed. It is found that the duration of voltage plateau depends on the rate of Li stripping, while the stripping rate is restricted by the capability of Li+ intercalation into graphite. Parameters like intercalation kinetics, solid-state diffusivity of graphite and cell temperature can substantially influence the voltage curves even with the same amount of Li plating. Further, we report an interesting phenomenon that during Li stripping one part of anode near the separator has net oxidation current (local stripping rate > intercalation rate), providing Li+ ions and electrons to the other part of anode near the foil which has net reduction current.
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•We present a Li-ion battery model incorporating both Li plating and stripping.•Voltage plateau after charging due to by Li stripping is captured and analyzed.•Length of voltage plateau depends highly on capability of graphite intercalation.•Anode splits into to two parts during Li stripping.•Differential voltage approach to quantify Li plating amount is assessed.
Inducing protein degradation by proteolysis targeting chimeras (PROTACs) has gained tremendous momentum for its promise to discover and develop new therapies. Based upon our previously reported ...PROTAC MDM2 degraders, we have designed and synthesized additional analogues. Surprisingly, we found that simple structural modifications of MD-222, a bona fide MDM2 PROTAC degrader, converts it into a “molecular glue”, as exemplified by MG-277. MG-277 induces only moderate MDM2 degradation and fails to activate wild-type p53 but is highly potent in inhibition of tumor cell growth in a p53-independent manner. Our mechanistic investigation established that MG-277 is not a PROTAC MDM2 degrader but instead works as a molecular glue, inducing degradation of a translation termination factor, GSPT1 to achieve its potent anticancer activity. Our study provides the first example that simple structural modifications can convert a bona fide PROTAC degrader into a molecular glue compound, which has a completely different mechanism of action.
The radial drift and diffusion of dust particles in protoplanetary disks affect both the opacity and temperature of such disks, as well as the location and timing of planetesimal formation. In this ...paper, we present results of numerical simulations of particle-gas dynamics in protoplanetary disks that include dust grains with various size distributions. We have considered three scenarios in terms of particle size ranges, one where the Stokes number τs = 10−1−100, one where τs = 10−4−10−1, and finally one where τs = 10−3−100. Moreover, we considered both discrete and continuous distributions in particle size. In accordance with previous works we find in our multispecies simulations that different particle sizes interact via the gas and as a result their dynamics changes compared to the single-species case. The larger species trigger the streaming instability and create turbulence that drives the diffusion of the solid materials. We measured the radial equilibrium velocity of the system and find that the radial drift velocity of the large particles is reduced in the multispecies simulations and that the small particle species move on average outwards. We also varied the steepness of the size distribution, such that the exponent of the solid number density distribution, dN∕da ∝ a−q, is either q = 3 or q = 4. Overall, we find that the steepness of the size distribution and the discrete versus continuous approach have little impact on the results. The level of diffusion and drift rates are mainly dictated by the range of particle sizes. We measured the scale height of the particles and observe that small grains are stirred up well above the sedimented midplane layer where the large particles reside. Our measured diffusion and drift parameters can be used in coagulation models for planet formation as well as to understand relative mixing of the components of primitive meteorites (matrix, chondrules and CAIs) prior to inclusion in their parent bodies.
Lithium-ion batteries with nickel-rich layered oxide cathodes and graphite anodes have reached specific energies of 250-300 Wh kg
(refs.
), and it is now possible to build a 90 kWh electric vehicle ...(EV) pack with a 300-mile cruise range. Unfortunately, using such massive batteries to alleviate range anxiety is ineffective for mainstream EV adoption owing to the limited raw resource supply and prohibitively high cost. Ten-minute fast charging enables downsizing of EV batteries for both affordability and sustainability, without causing range anxiety. However, fast charging of energy-dense batteries (more than 250 Wh kg
or higher than 4 mAh cm
) remains a great challenge
. Here we combine a material-agnostic approach based on asymmetric temperature modulation with a thermally stable dual-salt electrolyte to achieve charging of a 265 Wh kg
battery to 75% (or 70%) state of charge in 12 (or 11) minutes for more than 900 (or 2,000) cycles. This is equivalent to a half million mile range in which every charge is a fast charge. Further, we build a digital twin of such a battery pack to assess its cooling and safety and demonstrate that thermally modulated 4C charging only requires air convection. This offers a compact and intrinsically safe route to cell-to-pack development. The rapid thermal modulation method to yield highly active electrochemical interfaces only during fast charging has important potential to realize both stability and fast charging of next-generation materials, including anodes like silicon and lithium metal.
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•Proton conductive carboxylate-based MOFs were reviewed.•Aliphatic carboxylate-based and aromatic carboxylate-based MOFs were included.•Proton conductivity and conducting mechanism ...were discussed.•The future development trend of such MOFs is prospected.
As a significant type of crystalline solid proton conducting materials, metal–organic frameworks (MOFs) have been paid great attention and pursued by researchers. In this review, we will mainly summarize the proton conduction explorations of MOFs based on carboxylate ligands (including aliphatic carboxylate-based and aromatic carboxylate-based MOFs) from the aspects of synthetic strategies, stability, proton conductive properties and mechanism, application, etc. Finally, on the basis of summarization of literature and our own research on proton conduction, development prospects and challenges for such conductive materials in the future are highlighted.
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•NH2-MIL-125 displayed high adsorption capacity and fast kinetic towards Ag(Ⅰ).•The column study indicated NH2-MIL-125 could be used in large-scale application.•Both DFT calculations ...and XPS were used to reveal the adsorption mechanisms.•The Ag/C/TiO2 photocatalyst was obtained from the used NH2-MIL-125 by calcination.
In this work, NH2-MIL-125(Ti) were adopted to eliminate Ag(I) from the simulated silver-plating wastewater. The results revealed that NH2-MIL-125 exhibited superior adsorption performance toward Ag(I) ions with uptake capacity of 192.5 mg·g−1 to that of MIL-125 (139.8 mg·g−1) within 60 min. The isotherm and kinetic data were exactly fitted to both Langmuir and Pseudo-second-order models. The thermodynamic parameters like enthalpy change (ΔHo), entropy change (ΔSo) and Gibbs free energy change (ΔGo) confirmed that the adsorption process was spontaneous, exothermic and disordered. As well, the influencing parameters of the adsorption process like pH, adsorbent dose and foreign metal ions were examined. The fixed-bed column filled with NH2-MIL-125 powder immobilized onto cotton fiber could continuously adsorb Ag(I), which offered the possibility of achieving potential large-scale applications. The possible adsorption mechanism of NH2-MIL-125 toward Ag(I) primarily involved the electrostatic adsorption and coordinative interactions, which was further affirmed by the density functional theory (DFT) calculations. In addition, the used NH2-MIL-125 saturated with Ag(I) ions could be either desorbed to release the Ag(I) for NH2-MIL-125 re-generation or further calcinated into Ag/C/TiO2 photocatalyst to accomplish photocatalytic degradation toward organic pollutants like methylene blue (MB) and phenol. In this work, the 3Rs (reduce, recycle and reuse) approach was practiced, accomplishing that one stone killed three birds (pollutant elimination, resource recovery and resource utilization).
The synergistic efficacy of phototherapy and cancer immunotherapy is severely restricted by both the inherent photobleaching and aggregation‐caused quench (ACQ) defects of photosensitizers and the ...intrinsic antioxidant tumor microenvironment (TME), such as hypoxia and overexpressed glutathione (GSH). To address these issues, a novel porphyrin‐based staggered stacking covalent organic framework (COF), COF‐618‐Cu, is rationally designed as a reactive oxygen species (ROS) amplifier, owing to its excellent catalase‐like activity, COF‐618‐Cu is capable of consuming endogenous hydrogen peroxide to produce sufficient oxygen to alleviate the tumor hypoxia phenomena. Moreover the overexpressed intracellular GSH is also depleted to decrease the scavenging of ROS, due to the glutathione peroxidase mimic activity of COF‐618‐Cu. Mechanistic studies reveal that the unique staggered stacking mode between COF‐618‐Cu interlayers can effectively relieve both the photobleaching and ACQ effects that are inaccessible to commonly eclipsed COFs. These, combined with their excellent photothermal therapy performance, make COF‐618‐Cu favorable for inducing robust immunogenic cell death and remodeling TME to boost antitumor immunity.
A novel staggered stacking covalent organic framework (COF)‐based photosensitizer, COF‐618‐Cu, is reported, which can simultaneously alleviate photobleaching and aggregation‐induced quench effects to achieve desirable phototherapy performance and further elicit robust immunogenic cell death to trigger a durable antitumor immune response for boosting cancer immunotherapy.
Despite high‐energy density and low cost of the lithium–sulfur (Li–S) batteries, their commercial success is greatly impeded by their severe capacity decay during long‐term cycling caused by ...polysulfide shuttling. Herein, a new phase engineering strategy is demonstrated for making MXene/1T‐2H MoS2‐C nanohybrids for boosting the performance of Li–S batteries in terms of capacity, rate ability, and stability. It is found that the plentiful positively charged S‐vacancy defects created on MXene/1T‐2H MoS2‐C, proved by high‐resolution transmission electron microscopy and electron paramagnetic resonance, can serve as strong adsorption and activation sites for polar polysulfide intermediates, accelerate redox reactions, and prevent the dissolution of polysulfides. As a consequence, the novel MXene/1T‐2H MoS2‐C‐S cathode delivers a high initial capacity of 1194.7 mAh g−1 at 0.1 C, a high level of capacity retention of 799.3 mAh g−1 after 300 cycles at 0.5 C, and reliable operation in soft‐package batteries. The present MXene/1T‐2H MoS2‐C becomes among the best cathode materials for Li–S batteries.
Phase engineered MXene/1T‐2H MoS2‐C with plentiful S‐vacancy defects is highly effective for trapping polysulfide intermediates and accelerating redox kinetics, leading to the enhanced lithium–sulfur batteries.
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