Weak Dipole Effect Customized Zinc Ion‐Rich Protective Layer for Lean‐Electrolyte Zinc Metal Batteries
A zwitterionic protective layer is engineered on Zn surface by weak dipole effect of TMAO. The weak dipole effect realizes Zn ion-rich environment to alleviate the concentration polarization on electrolyte/Zn interface and exhibits short range interaction with free water to inhibit side reactions, thereby achieving enhanced performance for both symmetrical and full batteries with lean-electrolyte.
Abstract
The industrial development of Zn-ion batteries requires high performance even with lean-electrolyte. Nevertheless, lean-electrolyte can exacerbate concentration polarization at the interface of electrode/electrolyte, leading to significant Zn corrosion and battery failure. Here, a stable Zn ion-rich protective layer (TMAO-Zn) is constructed by a unique zwitterion structure of trimethylamine N-oxide (TMAO). The TMAO is characterized by the direct connection between positive and negative charges (N+-O−) with minimal dipole moment, which renders weak dipole interactions to form the TMAO-Zn layer with Zn2+, thereby reducing concentration polarization and promoting the rapid and uniform deposition of Zn2+. Furthermore, the O of TMAO-Zn exhibits the higher electrophilic index, indicating a stronger propensity for stable hydrogen bond interactions with active free water in the inner Helmholtz layer (IHL), thereby mitigating corrosion under extreme conditions of low electrolyte-to-capacity ratio (E/C ratio). Consequently, the symmetrical Zn battery with TMAO-Zn enables stable cycling for over 250 h with lean-electrolyte of 15 µL mA h−1. Additionally, Zn/I₂ pouch battery with a low E/C ratio of 21.2 µL mA h−1 provides ultra-high stable specific capacity of 96 mA h for over 250 cycles (capacity retention rate of 98.3%). This study offers a new concept to propel the practical application of Zn batteries with lean-electrolyte.
A High‐Throughput Approach to Identifying Environment‐Friendly Artificial Antisolvents for Efficient Perovskite Solar Cells
A high-throughput approach is used to screen 40 perovskite antisolvents and pinpoint specific regions favorable for the formation of high-quality perovskite films based on Hansen solubility parameters (HSPs). The low-toxicity candidates are obtained by adjusting the HSPs and validated for different perovskite compositions.
Abstract
Rapid crystallization facilitated by antisolvents is widely employed for producing high-quality perovskite films, but constrained by the limited variety and high toxicity of conventional solvents, underscoring the need for sustainable and low-toxicity solvent systems for large-scale production. In this study, a systematic screening of over 40 antisolvents is conducted using a high-throughput platform, uncovering a significant correlation between the antisolvent properties within Hansen solubility space and the structural and optoelectronic characteristics of the resultant perovskite films. A Hansen solubility sphere is subsequently constructed, pinpointing a specific region within this space that is most conducive to the formation of high-quality perovskite films. The underlying mechanism is further elucidated: antisolvents situated outside this optimal region either induce a rapid extraction of N,N-dimethylformamide (DMF), thereby limiting grain growth due to insufficient crystallization time or fail to adequately extract DMF. Since no ideal low-toxicity single antisolvent is found, a general concept based on solvent combinations with ultra-low-toxicity is introduced to solve the issues. The design rule for environment-friendly “artificial” solvents, which is validated for different perovskite compositions, paves the way for sustainable development and production of perovskite-based optoelectronic technologies.
Tunable Bipolar Photothermoelectric Response from Mott Activation for In‐Sensor Image Preprocessing
This study introduces a gate-tunable bipolar photothermoelectric detector using a vanadium dioxide film transistor. The device offers broadband photoresponse, linear light-intensity dependence, adjustable responsivities, low energy use (8 pJ per spike), and high stability (over 5000 cycles). An integrated convolutional network excels in broadband image classification, medical image denoising, and retinal vessel segmentation, highlighting its potential for future smart edge sensors.
Abstract
In-sensor image preprocessing, a subset of edge computing, offers a solution to mitigate frequent analog-digital conversions and the von Neumann bottleneck in conventional digital hardware. However, an efficient in-sensor device array with large-scale integration capability for high-density and low-power sensory processing is still lacking and highly desirable. This work introduces an adjustable broadband photothermoelectric detector based on a phase-change vanadium dioxide thin-film transistor. This transistor employs a vanadium dioxide/gallium nitride three-terminal structure with a gate-tunable phase transition at the gate-source junctions. This design allows for modulable photothermoelectric responsivities and alteration of the short-circuit photocurrent's polarities. The devices exhibit linear gate dependence for the broadband photoresponse and linear light-intensity dependence for both positive and negative photoresponsivities. The device's energy consumption is as low as 8 pJ per spike, which is one order of magnitude lower than that of previous Mott materials-based in-sensor preprocessing devices. A wafer-scale bipolar phototransistor array has also been fabricated by standard micro-/nano-fabrication techniques, exhibiting excellent stability and endurance (over 5000 cycles). More importantly, an integrated in-sensor convolutional network is successfully designed for simultaneous broadband image classification, medical image denoising, and retinal vessel segmentation, delivering exceptional performance and paving the way for future smart edge sensors.
Processable and Recyclable Covalent Organic Framework Gel Electrolytes
The preparation of COF gels is demonstrated and presents a method for solution-based reconstruction of COF gel electrolytes, inspired by the operational principle of wedges. By introducing oxygen atoms into the framework, the interaction forces are modulated between the framework layers and introduce active sites for trifluoroacetic acid (TFA). This approach enables the exfoliation of COF layers, allowing them to be effectively dispersed as a nanosheet in an aqueous-TFA solution. Furthermore, by taking advantage of the dynamic nature of imine bond and controlling the ratio of TFA to water, this manages the competitive interactions between TFA, COF, and water molecules, enabling the reconfiguration of COF materials from nanosheet dispersions back to gels. The obtained gel material demonstrated exceptional cycling stability, and sustaining performance.
Abstract
Covalent organic framework (COF)-based electrolytes with abundant ordered channels and accessible interaction sites have shown great potential in energy storage and transformation, although their practical applications are strongly impeded by their inherent insolubility and non-melt processability. Developing processable COF gel electrolytes and recycling them remains a formidable challenge. In this study, the processing of COF to gels demonstrated through interlayer interaction manipulation and enable solution-reconstruction of COF gel electrolytes for the first time, inspired by the working principle of wedges. Good solution-processability of the COF powders in strong acid mediums is achieved by inserting oxygen atoms into its framework to promote the interlayer charge repulsion. This modification enabled the COF readily dispersable as colloidal nanosheets in an aqueous solution of trifluoroacetic acid (TFA). Starting from here, this is modulated competitive interactions among TFA, COF, and water molecules, to reconfigure COF materials between their gelified and colloidally dispersed states. The reconfigured COF gel maintains their mechanical properties and long cycle life as an electrolyte in the battery (>800 h). This approach realizes solution processing of COF powders and can recycle COF out of gels for repeated use, offering new insights and strategies for their preparation and sustainable recycling.
Fri 20 Jun 16:00: Title to be confirmed
Abstract not available
- Speaker: Professor Julio Cordioli, University of Santa Catarina,Brazil
- Friday 20 June 2025, 16:00-17:00
- Venue: JDB Seminar Room, CUED.
- Series: Engineering - Dynamics and Vibration Tea Time Talks; organiser: div-c.
Fri 02 May 16:00: Pianos, guitars and double decays
Some stringed instruments, such as the piano, have multiple strings associated with each note. This has a consequence for the sound which is not immediately obvious: coupling between the strings can produce a decay profile for the note which starts steep, but gives way to a slower decay later in the note. To an extent, a piano tuner can tailor this double-decay profile by subtle adjustments. The talk will explore the physics behind this phenomenon, and examine whether other stringed instruments would be expected to display a similar effect. A criterion based on a measurement of the soundboard vibration at the string’s attachment point will be developed, and illustrated with data from several different stringed instruments.
- Speaker: Professor Jim Woodhouse, Emeritus, CUED
- Friday 02 May 2025, 16:00-17:00
- Venue: JDB Seminar Room, CUED.
- Series: Engineering - Dynamics and Vibration Tea Time Talks; organiser: div-c.
Fri 13 Jun 16:00: Title to be confirmed
Abstract not available
- Speaker: Dr Zack X Conti, Alan Turing Institute
- Friday 13 June 2025, 16:00-17:00
- Venue: JDB Seminar Room, CUED.
- Series: Engineering - Dynamics and Vibration Tea Time Talks; organiser: div-c.
Fri 09 May 14:00: A variational structure underpinning higher-order homogenization
From an engineering point of view, it is convenient to describe composite materials using homo- geneous effective properties. When the microstructure is periodic, asymptotic homogenizationis particularly well suited for this aim. Classical homogenization corresponds to the dominant order model and yields an effective standard Cauchy medium. At next orders, we can derive addi- tional corrections that depend on the successive strain gradients. These corrections are typically of interest to capture size-effects appearing for microstructures with contrasted stiffness properties. However, these higher-order models present two major limitations. First, the corrections producedby homogenization can handle size-effects that occur in the bulk region, but are not suited to the analysis of the boundaries. In fact, they miss significant boundary effects which can degrade significantly the quality of the predictions. Secondly, these higher-order models present several mathematical inconsistencies, including non-positive strain-gradient stiffnesses. As a result, the effective energy is not necessarily positive and any equilibrium solution is unstable with respect to short-scale oscillations. To handle these two limitations simultaneously, we elaborate a newhomogenization procedure that includes boundary effects. By contrast with usual approaches, inour procedure the homogenization is carried at the energy level, rather than on the strong formof the equilibrium. Besides, the positivity of the resulting energy is guaranteed by an original truncation method [1]. As an example, we consider a 1D spring network. The resulting effective energy contains a bulk term that is positive, plus a boundary term that accounts for the energy generated by the boundary effects. We show that, by contrast with usual asymptotic homogenization, this higher-order model is able to capture size-effects occurring in the interior domain, as well as near the boundaries.
- Speaker: Manon Thbaut, Ecole Polytechnique
- Friday 09 May 2025, 14:00-15:00
- Venue: Oatley 1 Meeting Room, Department of Engineering.
- Series: Engineering - Mechanics and Materials Seminar Series; organiser: div-c.
Fri 06 Jun 16:00: Grain-scale models of transient diffusion creep
Abstract not available
- Speaker: John Rudge
- Friday 06 June 2025, 16:00-17:00
- Venue: Tea Room, Old House.
- Series: Bullard Laboratories Tea Time Talks; organiser: David Al-Attar.
Ordered Interfacial Domain Expansion Catalysis Enhances Hydrogen Evolution for Proton Exchange Membrane Electrolysis
DOI: 10.1039/D5EE00441A, PaperShu-Hong Yu, Mingrong Qu, Yu-Xiao Cheng, Sihua Feng, Jie Xu, JiaKang Yao, Wensheng Yan, Sheng Zhu, Liang Cao, Rui Wu
Metal/metal oxide composites represent a promising group of catalysts that can substantially reduce the platinum group metal (PGM) loading at the cathode for proton exchange membrane water electrolysis (PEM-WE). However,...
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Fri 13 Jun 15:30: Science advice under uncertainty
In this session, Amy Orben, the leader of the Digital Mental Health Group at the MRC Cognition and Brain Sciences Unit, will talk about her experience of having to support evidence-based policy in the area of teen mental health and social media. Her vision on how this could be improved was described in Orben, Amy, and J. Nathan Matias, ‘Fixing the science of digital technology harms’, Science 388, no. 6743 (2025): 152–155.
- Speaker: Amy Orben (MRC Cognition and Brain Sciences Unit)
- Friday 13 June 2025, 15:30-17:00
- Venue: Board Room, Department of History and Philosophy of Science.
- Series: Coffee with Scientists; organiser: Marta Halina.
Fri 30 May 15:30: The Culture Lab
Abstract not available
- Speaker: Helene Scott-Fordsmand (Clare Hall & HPS, Cambridge) and Anatolii Kozlov (Science & Technology Studies, UCL)
- Friday 30 May 2025, 15:30-17:00
- Venue: Board Room, Department of History and Philosophy of Science.
- Series: Coffee with Scientists; organiser: Marta Halina.
Fri 20 Jun 16:00: Title to be confirmed
Abstract not available
- Speaker: Zachary Sudholz
- Friday 20 June 2025, 16:00-17:00
- Venue: Tea Room, Old House.
- Series: Bullard Laboratories Tea Time Talks; organiser: David Al-Attar.
Fri 13 Jun 16:00: The splendours of Isfahan, Iran, enabled by Late Quaternary earthquake faulting and drainage reversal
Abstract not available
- Speaker: James Jackson
- Friday 13 June 2025, 16:00-17:00
- Venue: Tea Room, Old House.
- Series: Bullard Laboratories Tea Time Talks; organiser: David Al-Attar.
Fri 06 Jun 16:00: Title to be confirmed
Abstract not available
- Speaker: John Rudge
- Friday 06 June 2025, 16:00-17:00
- Venue: Tea Room, Old House.
- Series: Bullard Laboratories Tea Time Talks; organiser: David Al-Attar.
Fri 02 May 16:00: The tectonic, thermal, and temporal controls on the production of critical metal deposits
Abstract not available
- Speaker: Alex Copley
- Friday 02 May 2025, 16:00-17:00
- Venue: Tea Room, Old House.
- Series: Bullard Laboratories Tea Time Talks; organiser: David Al-Attar.
Substitution Index‐Prediction Rules for Low‐Potential Plateau of Hard Carbon Anodes in Sodium‐Ion Batteries
The substitution index of precursor (Δ) is established as an effective predictor for the low-potential plateau performance of hard carbon (HC) anodes in sodium-ion batteries. Three carbon models—disordered carbon, closed-pore-dominated carbon, and turbostratic carbon—are constructed to validate the accuracy of Δ and investigate the mechanisms of closed pore formation and sodium storage.
Abstract
Establishing prediction rules for the low-potential plateau (LPP) of hard carbon (HC) anodes is crucial for constructing high-energy-density sodium-ion batteries (SIBs). While current studies suggest that the closed pores of HC can enhance the LPP performance, the rules for directly predicting the LPP from precursors have yet to be established. Here, prediction rules for the LPP of HC anodes in SIBs—the substitution index (Δ) of precursor are introduced. Three carbon models (disordered carbon, closed-pore-dominated carbon, and turbostratic carbon) are constructed to verify the accuracy of Δ and to explore the closed-pore formation and LPP mechanism. In detail, as the Δ increases from 0.06 to 0.22, the LPP capacity rises from 25 to 278 mAh g⁻¹, revealing a strong linear correlation between Δ of precursor and LPP capacity. In situ XRD, Raman, and ex situ SAXS, EPR further confirm that sodium storage in HC can be categorized into adsorption (>0.4 V), interlayer storage (0.4 to 0.15 V), and pore-filling (below 0.15 V). This work not only elucidates the sodium storage mechanisms, but also provides one efficient design guideline for advanced carbon anodes in SIBs.
Modulating Coupled Polyhedral Distortion in Li‐Rich Cathodes for Synergistically Inhibiting Capacity and Voltage Decay
Based on density functional theory calculations, machine learning, and experimental validation, a general design approach is provided to suppress performance degradation by modulating coupled polyhedral distortion in layered cathode materials. The developed Li-rich cathode exhibits remarkable long-term capacity and voltage stability, with 95.8% capacity retention after 300 cycles and 0.02% voltage decay per cycle.
Abstract
Achieving significant enhancements in both capacity and voltage stability remains a formidable challenge for Li-rich layered cathodes. The severe performance degradation is attributed to large lattice strain, irreversible oxygen release and transition metal migration, but the most critical factor responsible for structural destabilization is still elusive. Here, based on density functional theory calculations, machine learning and experimental validation, a multi-hierarchy screening of complex multi-element doping systems is developed from electrochemical activity, lattice strain, oxygen stability and transition metal migration barrier. It is further identified that the coupled polyhedral distortion parameter D+σ2 of the substitution element is the most significant feature that affects the structural stability during cycling. The Li-rich layered cathode developed based on the predicted results exhibits remarkable long-term capacity stability (95.8% capacity retention over 300 cycles) and negligible voltage loss (0.02% voltage decay per cycle). This study provides a general approach by modulating coupled polyhedral distortion for the rational design of cathode materials and can be expanded to the discovery of other advanced electrodes.
Developing Quasi‐Solid‐State Ether‐Based Electrolytes with Trifluorotoluylation Ionic Liquids for High Voltage Lithium Metal Batteries
This study proposes molecular design strategies to develop trifluorotoluylation ILs that enable quasi-solid-state ether-based electrolytes for high-voltage LMBs. The designed ILs greatly enhance the oxidative stability of the electrolyte and effectively suppress the dissolution of transition metal ions, facilitating the formation of a LiF-rich interfacial layer on the lithium anode, promoting uniform distribution of Li+ and regular deposition of lithium.
Abstract
The practical application of quasi-solid-state ether-based electrolytes is hindered by lithium dendrite formation and poor oxidation stability, which reduce the cycle life and energy density of the battery. Here, taking advantage of the ionic liquids’ high ionic interactions and structural flexibility in forming an optimized electrode/electrolyte interface, a pyrrolidinium-based ionic liquids with trifluorotoluylation cationic segment is designed and developed. The oxidation of anions in the electrolytes is induced to form a robust inorganic LiF-rich interphase at the cathode, thereby effectively achieving high oxidation stability and suppressing the dissolution of transition metal ions. In addition, the LiF interphases derived from the trifluorotoluylation cations increase the modulus of the anode interface and suppress the growth of lithium dendrites. Therefore, the Li-LiFePO4, Li-LiCoO2, and Li-LiNi0.8Co0.1Mn0.1O2 full cells with the optimized electrolytes demonstrate remarkable performance improvements at high current density (10 C), a wide voltage range of 4.5 V, a high mass loading of 11.1 mg cm−2, and a wide temperature range of −20–80 °C. Furthermore, a 2.66 Ah-level pouch cell with a high-energy-density of exceeding 356 Wh kg‒1 and excellent cyclic stability demonstrates the potential of the strategy in providing a path for the practical application of quasi-solid-state ether-based electrolytes in high-energy-density batteries.
From Metals to Polymers: Material Evolution and Functional Advancements in Current Collectors
The advantages, applications, challenges, and prospects of current collectors have been comprehensively reviewed, covering various types of metal current collectors, carbonaceous current collectors, conductive polymer current collectors, and organic–inorganic hybrid current collectors. The high-performance, multi-structured, and functionalized novel current collectors play a crucial role in advancing batteries with high performance, safety, and intelligence for next-generation energy storage devices.
Abstract
The rapid advancement of rechargeable batteries is hindered by insufficient energy density, limited design flexibility, and safety concerns, which pose significant challenges to their practical application. This review summarizes the crucial yet often overlooked role of current collectors in addressing these challenges. Recent progress across four types of current collectors, deriving from metal foils, carbonaceous substrates, conductive polymers, and organic–inorganic hybrids is systematically analyzed. Metal foils, as the most widely used current collectors, now face challenges including corrosion susceptibility and high volumetric density. Carbonaceous and polymer-based alternatives offer lightweight design and structural flexibility, but face limitations in conductivity and scalable production. Notably, organic–inorganic hybrid current collectors, leveraging material engineering and hierarchical design, offer a promising avenue to enhance battery safety and intelligence. Further, potential directions for current collector development, emphasizing 1) enhanced battery performance, 2) multiscale structural adaptability, and 3) integrated multifunctional design, providing prospective insights for next-generation energy storage devices are outlined.