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Boric acid-added 2D layered tin-based perovskite ((4-Cl-PEA)2SnI4) films utilize new Sn→B donor-acceptor interactions to suppress Sn2+ oxidation, resulting in reduced nonradiative recombination, low trap density, and high uniformity. This enables a vertical optoelectronic synapse with excellent synaptic performance. Finally, a high-resolution neuromorphic imaging array for image recognition, memory, and processing surpasses traditional image sensors.

Abstract

Lead-free tin-based perovskites, specifically (4-Cl-PEA)2SnI4, possess significant potential for the development of high-performance, robust neuromorphic imaging sensors, owing to their superior optoelectronic properties and compatibility with conventional complementary metal-oxide-semiconductor fabrication techniques and silicon-based readout circuits. However, the excessive oxidation of Sn2+ remains a significant obstacle, leading to suboptimal synaptic performance and low resolution in the neuromorphic imaging sensors due to increased recombination losses and poor film uniformity. This study first demonstrates that the introduction of novel Sn→B donor–acceptor bonding interactions effectively suppresses Sn2+ oxidation, enhancing uniformity, reducing nonradiative recombination, and improving synaptic plasticity. A vertical optoelectronic synapse demonstrates diverse synaptic behaviors, attributed to hole trapping and detrapping at the device interface. Additionally, the device enables applications in associative learning, neuromorphic computation, letter encoding, and handwritten digit recognition. Ultimately, integration with silicon circuits results in a high-resolution (32 × 32) neuromorphic imaging array, one of the highest reported resolutions for perovskite optoelectronic synapse arrays. The improved uniformity of boric acid-added (4-Cl-PEA)2SnI4 perovskite films significantly reduces photo response non-uniformity, enhances resolution, and improves memory capabilities. This neuromorphic imaging array successfully integrates sensing, storage, and computation, enabling advanced functionalities like letter recognition, memory, and processing, surpassing conventional image sensors.

Energy Environ. Sci., 2025, Accepted Manuscript
DOI: 10.1039/D4EE06003B, PaperGuoqiang Liu, Linyu Hu, Ying Liu, Mao-Wen Xu, Jiajun Guo, Haichuan Zhou, Guoliang Ma, He Lin, Zhenhuang Su, Chang Liu, Jiangqi Zhao, Chunlong Dai, Zifeng Lin
Current strategies to improve the low-temperature performance of aqueous batteries typically comes at the cost of safety, reaction kinetics, or overall energy density. Besides, the existing cathodes of low-temperature aqueous...
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AI Meets Economics: The Case of Auction-Assisted AI Systems in Cloud-Edge Continuum

Many cloud and edge AI services today perform machine learning inference in real time on end user requests. Over time, however, models could degrade in accuracy due to data and concept drifts, and full retraining can be infeasible because of limited training data, long training delay, and prohibitive computational overhead. A promising solution is for the AI service to incorporate externally supplied pre‑trained models to maintain resilience and accuracy in the face of evolving inputs. To incentivize third‑party model providers, who alone possess the requisite resources and data, to produce and contribute models, an economic mechanism is required to monetize their contributions. Auction formats naturally suggest themselves, yet they introduce fundamental challenges in this circumstance: the interdependence of sequential auctions, the trade‑off between system overhead and inference performance, and the need to balance economic properties with sustained participation. In this talk, firstly, I will formulate the repeated model‑procurement auctions as a non‑linear mixed‑integer social cost minimization problem, design a suite of polynomial‑time approximation algorithms that jointly solve this problem in an online manner, and describe the multiple performance guarantees of our approach, including per‑auction truthfulness and individual rationality, an upper bound on inference loss, and a parameterized‑constant competitive ratio for social cost, all supported by empirical evaluations. Afterwards, I will briefly survey our other efforts on auction‑assisted AI systems, including edge AI inference over auctioned resources and foundation model fine‑tuning with auction‑based pricing. Finally, I will conclude with a vision for future research.

Biography: Lei Jiao received his Ph.D. in computer science from the University of Göttingen, Germany, in 2014. He is currently a faculty member at the University of Oregon, USA , and was previously a member of the technical staff at Nokia Bell Labs, Ireland. He researches networking and distributed computing, spanning AI infrastructures, cloud/edge networks, energy systems, cybersecurity, and multimedia. His work integrates mathematical methods from optimization, control theory, machine learning, and economics. He has authored over 80 peer-reviewed publications in journals such as IEEE Transactions on Networking, IEEE Transactions on Mobile Computing, IEEE Transactions on Parallel and Distributed Systems, and IEEE Journal on Selected Areas in Communications, and in conferences such as INFOCOM , MOBIHOC, ICDCS , SECON, ICNP , ICPP, and IPDPS , garnering over 6,000 citations according to Google Scholar. He is a recipient of the U.S. National Science Foundation CAREER Award, the Ripple Faculty Fellowship, the Alcatel-Lucent Bell Labs UK and Ireland Recognition Award, and several Best Paper Awards including those from IEEE CNS 2019 and IEEE LANMAN 2013 . He has served in various program committee roles, including as a track chair for ICDCS , as a member for INFOCOM , MOBIHOC, ICDCS , and WWW , and as a chair for multiple workshops with INFOCOM and ICDCS .

• Speaker: Speaker to be confirmed
• Friday 23 May 2025, 15:00-16:00
• Venue: Computer Lab, FW11 and Online (MS Teams link to appear below).
• Series: Computer Laboratory Systems Research Group Seminar; organiser: Richard Mortier.

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CamVet Clinial Research Grants

Tom Kearns: ‘Confirming lymph node metastasis in canine mast cell tumours: A new tool in our KIT ’

• Speaker: Bruno Lopes, Jose Novo Matos, and Tom Kearns, Department of Veterinary Medicine
• Friday 26 September 2025, 08:45-10:00
• Venue: LT2.
• Series: Friday Morning Seminars, Dept of Veterinary Medicine; organiser: Fiona Roby.

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Metrics and random walks on 2D critical percolation and CLE

Intrinsic metrics (a.k.a. chemical distance) and random walks on percolation models have been attracting a lot of mathematical attention. The case of (low-dimensional) critical percolation, however, has remained poorly understood. In this talk, I will explain how to construct the scaling limits of the intrinsic metric and the random walk on 2D critical percolation clusters. More generally, for each CLE _\kappa, \kappa \in ]4,8[, we construct the canonical shortest-path metric and diffusion process on its gasket. We show that the metrics are uniquely characterised by their Markovian property, and that they are scale-covariant and conformally covariant.

This talk is based on joint works with Valeria Ambrosio, Irina Đanković, Maarten Markering, and Jason Miller.

• Speaker: Yizheng Yuan
• Tuesday 13 May 2025, 14:00-15:00
• Venue: MR12.
• Series: Probability; organiser: Jason Miller.

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In this study, a modular electrode system is designed by employing nanozyme-embedded microreactor units as independent reaction modules and establishing a fully connected cascaded neural network topology to enable efficient inter-module interconnection and synergistic optimization.

Abstract

Enhancing the redox kinetics of electrodes, achieving synergistic optimization of local energy conversion and overall charge transfer, and overcoming the technical bottleneck of significant performance degradation due to local unit failure in traditional electrode systems are crucial for developing high-rate lithium-sulfur batteries. Here, a modular cathode system (CoB1N3-MR/FNN) with a fully connected cascade neural network topology (FNN) is designed by constructing microreactor modules (CoB1N3-MRs) with embedded nanozymes (Co-B1N3), ordering and efficiently interconnecting them. This system not only enables efficient energy conversion within individual microreactors but also significantly enhances the long-range charge transport efficiency and energy aggregation capacity of the electrodes. Furthermore, CoB1N3-MR/FNN achieves fault tolerance to local damage through its distributed energy storage units and redundant charge transport channels. This synergistically enhanced modular electrode system for energy conversion and charge transport exhibits high specific discharge capacity (0.2 C, 1211 mAh g−1) and excellent rate capability (5 C, 731.26 mAh g−1; 10 C, 471.05 mAh g−1), and shows outstanding electrochemical performances in high sulfur loading, low electrolytes, and flexible pouch batteries (0.2 C, 1165 mAh g−1), fully demonstrating its practical application value.

The electronic configuration of Mn single-atom sites is regulated from low-spin to high-spin states by embedding well-defined molybdenum phosphide nanocrystals nearby (MoP@MnSAC-NC). The electronic phosphide-support interaction between MoP and Mn single atoms drives the electronic structure transition in Mn sites from low-spin to high-spin states, and this transition expedites both O2 adsorption and OH− desorption. The MoP@MnSAC-NC displays an outstanding alkaline oxygen reduction reaction performance.

Abstract

Oxygen reduction reaction (ORR) kinetics are closely related to the electronic structure of active sites. Herein, a single-atomic Mn catalyst decorated with adjacent MoP nanocrystals (MoP@MnSAC-NC) is reported. The decoration of MoP drives the electronic structure transition of Mn sites from low-spin to high-spin states through an electronic phosphide-support interaction. The rearranged electron occupation in 3dxz-yz and 3dz 2 orbitals of Mn sites leads to electrons occupying the σ orbital in Mn─*O2, thereby favoring O2 adsorption to initiate the ORR mechanism. In situ characterizations confirm that Mn 3dz 2 orbital occupation state can activate molecular O₂ and optimize the adsorption of the *OOH intermediate. As a result, the MoP@MnSAC-NC displays an outstanding alkaline ORR half-wave potential (E 1/2 = 0.894 V), excellent peak power densities (173/83 mW cm−2 for liquid/solid-state Zn-air batteries, respectively), and long-term stability (840 h) superior to commercial Pt/C. This work provides profound insights into spintronics-level engineering, guiding the design of next-generation high-performance ORR catalysts.

The highest experimentally determined focusing efficiency is reported here by using the direct imprinting of all-inorganic TiO2 metalens arrays. Absolute efficiency greater than 80% and relative efficiency greater than 90% are achieved by optimization of all fabrication parameters controllable in the additive manufacturing process. The highest refractive index of 2.3 is demonstrated by a short post-imprint ALD process.

Abstract

Highly efficient metalens arrays designed for 550 nm are directly printed using UV-assisted nanoimprint lithography (UV-NIL) and a TiO2 nanoparticle (NP)-based ink on 8″ optical wafers with imprint times less than 5 min. Approximately one-thousand 4-mm metalenses are fabricated per wafer with uniform optical performance using a reusable PDMS-based elastomeric stamp. The absolute and relative focusing efficiencies are as high as 81.2% and 90.4%, respectively, matching closely with the simulated maximum efficiencies of 83% and 91% achievable with the given master design, indicating that future improvements are possible, and efficiencies are not limited by materials or process. The imprinted metalenses are free from organics due to a post-imprint calcination step and exhibit outstanding dimensional and optical stabilities. The highest efficiencies are attained using imprint formulations comprised of mixtures of 10 and 20 nm TiO2 NPs, whose denser packing not only increases the refractive index (RI) of the calcined lenses up to 2.0 but also reduces the feature shrinkage relative to the master. 25 cycles of atomic layer deposition of TiO2 following imprinting increase the RI up to 2.3 without changing dimensions by uniform gap filling between NPs. This work opens a path for true, full-scale additive manufacturing of metaoptics.

Nucleation-layer assisted strategy is developed to achieve quasi-2D Ruddlesden-Popper Sn-based perovskite film with an intermediate-n-value dominated narrow phase distribution, vertical crystal orientation, and superior morphology, which enables device with champion efficiency of 11.18% and a record oxygen stability for Sn-based perovskite solar cells.

Abstract

Tin (Sn)-based perovskite solar cells (PSCs) are extremely vulnerable to oxygen. Nevertheless, mechanism understanding and fundamental strategies to achieve oxygen-stable Sn-based PSCs are lacking. Here a nucleation-layer assisted (NLA) strategy by forming nucleation layer at the interface of hole transport layer and perovskite to attain highly oxygen-stable quasi-2D Ruddlesden-Popper (RP) Sn-based PSCs is reported. The formation process of nucleation layer consists of washing off the prepared perovskite film and annealing the residue on the substrate, which produces a new substrate for perovskite film fabrication. Such nucleation layer can transform the subsequently deposited perovskite film from a small-n-value dominated wide phase distribution with random crystal orientation into an intermediate-n-value dominated narrow phase distribution with vertical crystal orientation. This nucleation layer also improves the perovskite film morphology with highly coadjacent flake-like grains, leading to reduced grain boundaries and pinholes. The resultant NLA perovskite film shows more efficient carrier transport capability, lower exciton-binding energy, weakened electron-phonon coupling, and significantly decreased oxygen diffusion rate upon oxygen exposure. Consequently, a quasi-2D RP Sn-based PSC with a champion efficiency of 11.18% is obtained. The unencapsulated device preserves 95% of its initial efficiency after a 2700-h oxygen aging test, creating a record oxygen stability for Sn-based PSCs.

This work reveals the role of interfacial Zn─N bonds in enhancing charge transfer and optimizing energy band alignment in S-scheme ZnO/covalent organic framework heterojunctions. Theoretical calculations, X-ray absorption spectroscopy, and femtosecond transient absorption spectroscopy confirm the mechanism, providing molecular-level insights into charge transfer processes and guiding the design of efficient photocatalysts for artificial photosynthetic systems.

Abstract

Photocatalysis is a promising solution to global energy shortage and environmental problems. Inspired by photosynthesis, multicomponent heterostructured photocatalysts are extensively investigated, and step-scheme (S-scheme) heterojunction has emerged as the theoretical basis for delineating charge transfer processes in predominant heterostructured photocatalysts. However, the specific charge transfer pathway across an S-scheme heterojunction remains elusive from an atomic/molecular perspective. Herein, it is demonstrated that in S-scheme heterojunction photocatalysts composed of imine-based covalent organic frameworks and nanostructured zinc oxide, interfacial Zn─N bonds are formed between the two components and play critical roles as a charge transfer gateway in the S-scheme heterojunction, based on theoretical calculations, X-ray absorption spectroscopy, and X-ray photoelectron spectroscopy. Moreover, mechanisms for enhanced charge transfer across the S-scheme heterojunction are elucidated using femtosecond transient absorption spectroscopy. This work provides new insights into molecular-level understanding of charge transfer mechanisms in S-scheme heterojunction photocatalysts for promoting energy and environmental applications of artificial photosynthesis.

Out-of-plane chemically ordered Ti4MoSiB2 MAB materials with high phase content are synthesized. This material shows desirable comprehensive mechanical properties over a wide temperature range and excellent lubricating and wear resistance performance at high temperatures, since the typical crystal structure and tribological chemical reactions. This discovery opens a door to high-temperature wear-resistant structural materials.

Abstract

As a newly emerging class of materials, quaternary layered borides are promising structural–functional integration materials. However, there have been very few systematic and in-depth studies in many areas of these materials, including high-temperature lubrication. In this study, a novel out-of-plane chemically ordered Ti4MoSiB2 MAB phase material is synthesized and its mechanical and tribological properties are investigated over a wide temperature range. Experiments and calculations are conducted to determine its mechanical failure, friction, and wear mechanisms. The results indicate that the synthesized material maintains desirable comprehensive mechanical properties from room temperature to 1273 K and exhibits excellent lubricating and wear resistance performance at high temperatures. In this study, the operating principles of the anisotropic thermal expansion of crystals on the fracture behaviors, and the tribological chemical reactions and oxygen vacancies on tribological properties, are explained. This study is expected to provide a foundation for future practical applications in high-temperature environments.

Dynamic molecular rotors are used to construct smart lanthanide metal–organic frameworks (Ln-MOFs) emitters with adaptive antenna effects for the first time and precisely regulated the energy transfer pathways of Ln-MOFs to achieve efficient multicolor luminescence switching behavior, upconversion luminescence, multiple smart anti-counterfeiting applications, purity monitoring of commercial gadolinium salts, smart photoresponsive specific antibiotics and amino acids.

Abstract

In this work, dynamic molecular rotors are used to construct smart lanthanide metal–organic frameworks (Ln-MOFs) emitters with adaptive antenna effects for the first time. The movement or distortion of the molecular rotors can be easily regulated by temperature changes, thereby inducing a dynamically changing antenna effect that can automatically match different lanthanide ions, achieving cyclic multicolor luminescence switching behavior and extremely complex multiple encryption anti-counterfeiting technology. In addition, by regulating the doping ratios of Gd(III) and Tb(III) with Eu(III) within the Ln-MOFs, differentiated energy transfer pathways are discovered, and red light emission very close to the BT.2020 color gamut standard is obtained. Gd0.99Eu0.01-MOF containing only 1% Eu(III) can show bright red luminescence, and in the range of 1–9% Eu(III) content, the characteristic emission intensity of Eu(III) ions and the content show an excellent linear relationship with a slope k as high as 2299. This can be used to identify the content of Eu(III) ions impurities in gadolinium salts from different manufacturers. Eu/Tb-MOF showed highly sensitive and visualized smart photoresponse behaviors to specific antibiotics and amino acids, respectively, with detection limits of 3.2/2.7 nM (tetracycline), 1.7/15.5 nM (oxytetracycline), 0.13/0.97 nM (aspartic acid), and 0.26/1.16 nM (glutamic acid).

WO3//MnO2-based electrochromic smart windows with highly selective visible and near-infrared regulation are achieved by decoupling the mechanisms of reversible deposition and ion adsorption. It is found that the hybrid Cu2+/Mn2+ ions promote proton adsorption while hampering proton insertion on the WO3 surface for the first time, endowing the windows with state-of-the-art properties.

Abstract

Electrochromic smart windows with dynamic photothermal management can enhance living comfort and reduce building energy consumption. However, they usually suffer from low selectivity and optical modulation in visible (VIS) and near-infrared (NIR) regions owing to the coupled mechanism restriction. Here, the reversible deposition and ion adsorption in WO3//MnO2-based smart windows are decoupled using a hybrid electrolyte, realizing their independent and efficient VIS–NIR regulation. The Cu2+/Mn2+ ions in the hybrid electrolyte enhance proton adsorption on the WO3 surface while impeding proton insertion, imparting state-of-the-art NIR regulation to the WO3 electrode. Moreover, the synergy of protons and Cu2+/Mn2+ ions facilitates reversible MnO2 electrodeposition on the electrode, triggering independent tuning of VIS light with an optical modulation of 94%. The outdoor test and simulation reveal that the smart window achieves cooling at 5–10 °C, an energy savings of 73.2 MJ m−2 and a reduction of 14.4 kg of CO2 emissions per square meter of the building annually. This work would contribute to energy-saving and emission-reduction solutions in widespread applications.

The rigid ultra-micropores are constructed by confining the semi-rigid sulfonated poly(ether ether ketone) molecules in graphene oxide nanochannels and fixing them with an amphiphilic molecule. The power density of the membrane can reach up to 371.65 W m−2 with high temperature (60 °C) hypersaline brine (5M/0.5M), which can be obtained from a solar stiller.

Abstract

Osmotic energy is a promising renewable energy source for its giant reserves and can be easily harvested with ion selective membranes. However, the output power density in membrane-scale applications is always below 10 W m−2 due to the high resistance from low salinity solution and the serious concentration polarization phenomenon. Here, this study shows that rigid ultra-micropores can greatly improve the output power density of the osmotic energy conversion process with high-temperature hypersaline brine. The membrane with rigid ultra-micropores is constructed by confining the high-content semi-rigid sulfonated poly(ether ether ketone) molecules in graphene oxide nanochannels and fixing them with amphiphilic molecules. The output power density of the membrane can be as high as 175.1 W m−2 with an energy conversion efficiency of 44.5% at the salinity gradient of 5 M/0.5 M, which can further increase to 371.65 W m−2 when the solution temperature is up to 60 °C. This study also demonstrates that the high-temperature hypersaline brine can be obtained from a passive solar stiller. The molecular engineering of ion selective membranes and the optimization strategy of the reverse electrodialysis process will inspire the development of a next-generation osmotic energy harvesting system.

Layer-by-layer deposition technology is combined with a trimer-induced pre-swelling (TIP) strategy by incorporating a 3D star-shaped trimer (BTT-Out) into the buried D18 donor layer to construct thick-film OSCs. A best performance of 20.3% (thin-film) and 18.8% (thick-film) with upgraded stability is achieved in TIP devices, among one of the highest performances reported of thick-film OSCs.

Abstract

Thick-film (>300 nm) organic solar cells (OSCs) have garnered intensifying attention due to their compatibility with commercial roll-to-roll printing technology for the large-scale continuous fabrication process. However, due to the uncontrollable donor/acceptor (D/A) arrangement in thick-film condition, the restricted exciton splitting and severe carrier traps significantly impede the photovoltaic performance and operability. Herein, combined with layer-by-layer deposition technology, a twisted 3D star-shaped trimer (BTT-Out) is synthesized to develop a trimer-induced pre-swelling (TIP) strategy, where the BTT-Out is incorporated into the buried D18 donor layer to enable the fabrication of thick-film OSCs. The integrated approach characterizations reveal that the exceptional configuration and spontaneous self-organization behavior of BTT-Out trimer could pre-swell the D18 network to facilitate the acceptor's infiltration and accelerate the formation of D/A interfaces. This enhancement triggers the elevated polarons formation with amplified hole-transfer kinetics, which is essential for the augmented exciton splitting efficiency. Furthermore, the regulated swelling process can initiate the favorable self-assembly of L8-BO acceptors, which would ameliorate carrier transport channels and mitigate carrier traps. As a result, the TIP-modified thin-film OSC devices achieve the champion performance of 20.3% (thin-film) and 18.8% (thick-film) with upgraded stability, among one of the highest performances reported of thick-film OSCs.

Energy Environ. Sci., 2025, Accepted Manuscript
DOI: 10.1039/D5EE00563A, PaperBiao Shi, Pengfei Liu, Zetong Sunli, Wei Han, Cong Sun, Ying Liu, Yuan Luo, Jin Si, pengcheng Du, Fu Zhang, Miao Yang, Yongcai He, Bo He, Dekun Zhang, Xiaona Du, Xixiang Xu, Rui Xia, Xueling Zhang, Yifeng Chen, Jifan Gao, Ying Zhao, Xiaodan Zhang
The evaporation-solution sequential deposited wide bandgap perovskite has been widely applied to fabricate efficient, commercial textured perovskite/silicon tandem solar cells. However, current works generally widened the bandgap by incorporating more...
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100 years of educational trials – no significant difference?

Randomised controlled trials (RCTs) in education research have been carried out for over 100 years. Over the last 15 of these years their use has increased significantly. In this talk we examine the field of education research to address the key challenges faced by education trials today and possible solutions. Despite their growing use they have been subject to sustained and rather trenchant criticism from significant sections of the education research community. There are key areas in which RCTs require focus and improvement: in particular in recruitment and retention, implementation and outcome measures.

• Speaker: Riikka Hofmann, Faculty of Education
• Wednesday 26 November 2025, 19:15-21:00
• Venue: City House, Hills Road, Cambridge CB2 1RY.
• Series: Cambridge Statistics Discussion Group (CSDG); organiser: Peter Watson.

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Title to be confirmed

Abstract not available

• Speaker: Professor Thomas E. Markland, Stanford University
• Wednesday 04 February 2026, 14:30-15:30
• Venue: Unilever Lecture Theatre, Yusuf Hamied Department of Chemistry.
• Series: Theory - Chemistry Research Interest Group; organiser: Lisa Masters.

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Parton showers beyond leading colour

General purpose parton showers are based on classical branching algorithms. As a result, it is not possible to account for even the leading quantum interference effects in general scattering processes and this often limits the accuracy of these showers to the leading colour approximation. We have developed the CVolver Monte Carlo code, which is able to evolve a density matrix to a prescribed accuracy in colour. This means we are able to account for wide-angle, soft-gluon physics systematically in 1/N where N=3 is the number of colours. This is the first time such a systematic resummation has been performed for general processes and in this talk I will report on the latest results.

• Speaker: Jeffrey R. Forshaw (Manchester U.)
• Friday 07 November 2025, 16:00-17:00
• Venue: Ray Dolby Centre, Seminar Room - North (Floor: 0 A0.019).
• Series: HEP phenomenology joint Cavendish-DAMTP seminar; organiser: Terry Generet.

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Nature Nanotechnology, Published online: 08 May 2025; doi:10.1038/s41565-025-01886-4

The interfacial dynamics in high-potential lithium batteries with polymer electrolytes have been challenging to characterize. Now, X-ray synchrotron analyses reveal that the rearrangement of ion-conductive phases in polymer electrolytes at electrode|electrolyte interfaces disrupts ionically conductive paths and contributes to battery performance degradation.