Abstract Halide perovskite nanochemistry is evolving at an unprecedented pace, rapidly expanding the scope of these materials from fundamental model systems to platforms with growing impact across both classical and quantum light technologies. In this perspective, we follow perovskite quantum dots (pQDs) from their birth in solution to their fully developed structural and photophysical complexity, highlighting recent advances, offering a critical view on current limitations, and discussing open questions together with possible paths forward. We hope this perspective helps inspire the next generation of ideas, tools, and design principles needed to unlock the full potential of pQDs.
Abstract Achieving an ideal bi-continuous network in organic solar cells requires balancing molecular self-assembly and film-formation kinetics. For strong-interaction polymers like D18, intense backbone interactions often lead to kinetically trapped, disordered states. Here, we present a molecular symmetry-breaking strategy using an asymmetric small-molecule donor, BC-A2O, as a guest regulator. Compared with its symmetric counterpart BC-A4O, BC-A2O features a rigid rhodanine hook and higher liquid-crystal Gibbs free energy difference. This strong thermodynamic drive enables BC-A2O to preferentially anchor onto D18 chains, establishing solution-phase interfacial pre-structuring that seeds a highly ordered fibrillar host network with optimized charge transport channels. Consequently, BC-A2O-based ternary devices achieve a benchmark efficiency of 20.53% (versus 19.46% for the binary baseline) with a fill factor of 81.16%. This work demonstrates the power of small-molecule donors in orchestrating hierarchical assembly for advanced photovoltaics.
Abstract Composite solid polymer electrolytes (CSPEs) have emerged as promising candidates for next-generation lithium metal batteries. However, the spatial evolution of the solid electrolyte interphase (SEI) at solid-state interfaces remains poorly understood despite its critical role in lithium metal stability. Herein, the anion-trapping layered double hydroxide (LDH) is introduced to poly(ethylene oxide)-based CSPEs to regulate Li+ transport and stabilize the lithium/electrolyte interface. The LDH-enhanced electrolyte achieves exceptional cycling stability over 950 h with a lithium electrode and 90.1% capacity retention after 250 cycles in LiFePO4||Li full cells. Operando nano-focus wide-angle X-ray scattering maps the spatial distributions of both the SEI and lithium dendrites at the lithium/electrolyte interface across micron-scale lateral and vertical dimensions. The regulated Li+ flux promotes homogeneous lithium deposition and the formation of a robust, multifunctional SEI, thereby suppressing lithium dendrite growth and stabilizing the interface. This study provides direct visualization of SEI evolution in CSPEs and clarifies its role in dendrite-free all-solid-state lithium metal batteries.
Abstract Unstable low-valent Mn species at LiNi0.5Mn1.5O4 surfaces contribute to surface degradation, yet the electronic mechanism underlying their formation remains insufficiently understood. Through a systematic first-principles investigation across lithiation states, low-index facets, and surface terminations, we find that surface oxygen exhibits enhanced electronic activity and acts as a key mediator of local charge compensation. Surface-specific and delithiation-induced coordination changes, oxygen-vacancy formation, and electrolyte-derived surface-O protonation provide distinct structural, defect, and interfacial perturbations of the local surface-O environment. Collectively, these perturbations converge on local O–Mn charge redistribution, promoting electron accumulation and reduction at neighboring Mn sites and supporting a unified surface-O-mediated pathway for near-surface Mn reduction. A multi-descriptor framework based on local X–O–Mn units further evaluates dopant regulation of oxygen activity and Mn electronic states. More broadly, these mechanistic insights provide an atomistic basis for the mechanism-guided design of spinel cathodes.
Abstract Low-grade industrial waste heat (<300 °C) is abundant yet largely unutilized. Low-temperature steam electrolysis (100–300 °C) could exploit this resource, but progress is limited by the lack of electrolytes that combine high proton conductivity with mechanical and chemical stability. Here, we report a “soggy sand” electrolyte based on ammonium scandium pyrophosphate (NH4ScP2O7) formed directly from phosphoric-acid-rich aqueous solutions. The material comprises a percolated phosphoric acid phase confined within a nanoparticle framework, yielding a viscoelastic solid that enables fabrication of self-standing, gas-tight membranes by simple pressing. The membranes exhibit proton conductivity >10–2 S cm–1 at 150 °C with a tensile strength of ∼7 MPa. Steam electrolysis using the ScP34 membrane operates stably at 0.35 A cm–2 for 150 h, with a cell voltage of ∼1.6 V and a Faradaic efficiency exceeding 95%. This work establishes a design strategy for efficient hydrogen production from low-temperature waste heat.
Abstract Near-infrared tin perovskite light-emitting diodes (PeLEDs) constitute a class of lead-free optoelectronic devices, but their performance suffers from rapid crystallization over a defective hole transport layer underneath the perovskite film. Here, we report a buried-interface kinetic regulation strategy for Cs-rich tin iodide perovskites. The buried interlayer regulated the initial growth of the perovskite film. This regulation delayed the emergence of emissive domains and promoted compact film growth without substantially perturbing the Sn-I framework. Spectroscopic and theoretical analyses reveal interfacial interactions with Sn-related sites, which help suppress defect formation and nonradiative losses. The optimized PeLEDs exhibited near-infrared electroluminescence centered at 945 nm and achieved a peak external quantum efficiency of 8.04%. This work highlights buried-interface kinetic regulation as an effective route toward efficient lead-free near-infrared tin perovskite LEDs.
Abstract Phenoxazine-based compounds are valuable cathode materials owing to their high theoretical capacity and robust redox reversibility. However, insufficient intramolecular charge delocalization destabilizes deeply oxidized states and limits dual-electron transfer. Herein, a “push-pull electronic engineering” strategy is developed by incorporating delocalizing electron-deficient units into the phenoxazine framework to regulate frontier molecular orbitals, extend π-electron delocalization, and stabilize deeply oxidized states. Two isomers, 2,7-di(10H-phenoxazin-10-yl) tribenzo[a,c,i]phenazine-10,15-dione (2,7-DPTBD) and its 3,6-substituted counterpart (3,6-DPTBD), are synthesized. Both materials exhibit reversible dual-electron oxidation. Nevertheless, steric hindrance in 3,6-DPTBD weakens the push-pull interaction and reduces its electrochemical performance. Consequently, 2,7-DPTBD delivers a high energy density of 668 Wh kg–1 at an average discharge potential of 2.56 V. Furthermore, a full cell employing graphite anodes achieves a peak discharge capacity of 211 mAh g–1 and maintains stable cycling over 1000 cycles. Symmetric dual-ion batteries are assembled based on the bipolar characteristics of 2,7-DPTBD, which stably operate for 200 cycles.
Abstract We investigate the nanoscale function of additives used for tin-containing perovskites, using the archetypal FASnI3 (FA = formamidinium). First, we find that the addition of sodium borohydride (NaBH4) is inhomogeneous, with 200–500 nm aggregates forming on the FASnI3 surface. The inhomogeneous distribution of NaBH4 leads to a relatively small (∼1% of the film) amount of reduced perovskite, but the macroscopic properties are dominated by the overwhelming space without any treatment. Upon illumination, more aggregate regions (∼13%) become activated due to reduction of photogenerated I2. On the other hand, when we combine NaBH4 with dipropylammonium iodide (DipI) passivation and illuminate, we observe a much more homogeneous activation effect, which we attribute to denser coverage of NaBH4. We find that the iodine content in FASnI3 films treated with NaBH4 and DipI is 64% less than in those treated with NaBH4 alone. These results underline that the microscale configuration of different additives in tin perovskites is deeply interconnected and it is essential to uncover their chemical reactivity.
Abstract A central challenge in thermoelectric science is to break the intrinsic coupling between charge and heat transport. Herein, we demonstrate that thermally driven interface reconstruction in perovskite-modified skutterudites generates a hierarchical defect architecture that enables simultaneous regulation of electronic and phononic transport. By deliberately integrating point defects, (Pb, In)-rich nanoprecipitates, and multiscale pores into a unified interfacial framework, the reconstructed microstructure enhances carrier-energy selectivity while fostering broadband phonon scattering across multiple length scales. This synergy effectively mitigates the conventional electrical–thermal trade-off, yielding a peak zT of ∼1.76 at 773 K. A seven-couple thermoelectric generator assembled from the optimized material delivers a conversion efficiency of 8.1% under a temperature difference of 452 K. Collectively, these findings establish hierarchical interface reconstruction as a powerful strategy for transport decoupling and highlight defect-architecture engineering as a versatile design principle for thermoelectric energy conversion.
Abstract Surging global demand for lithium-ion batteries (LIBs) creates an urgent imperative to recover critical materials from spent cells at scale. Here we integrate a spinel LiMn2O4 (LMO) ceramic membrane with a bipolar membrane electrodialysis (BMED) architecture enables self-sustaining ion-exchange. Water dissociation at the bipolar membrane generates a continuous proton flux that drives stoichiometric H+/Li+ exchange within the LMO lattice, providing in situ pH regulation without external eluent circulation. By decoupling lithium extraction from the discontinuous intercalation-deintercalation cycles inherent to conventional electrochemical approaches, this design enables continuous ion transport and faster extraction kinetics. Under optimized conditions, the system recovers a lithium recovery flux of 0.255 kg m–2 day–1 with a purity of 99.75%. This experimentally measured rate corresponds to a projected recovery of 254.5 g of Li+ over 24 h using a 1 m2 membrane. This work demonstrates continuous-flow, high-purity lithium recovery and expands ceramic ion-exchange membranes to other critical-mineral separations.
Abstract Electrochemically induced direct air capture (DAC) has emerged as a compelling strategy for mitigating anthropogenic CO2 emissions. However, a critical bottleneck remains the O2 sensitivity of redox-active molecules, which directly degrades both capture efficiency and energy economy. Herein, we report a hybrid flow cell based on the proton-coupled electron transfer (PCET) of tribenzo[a,c,i]phenazine-10,15-dione (TBPDO) that drives pH-swing DAC. The O2 tolerance is enhanced by inducing intramolecular hydrogen bonds in the reduction product (r-TBPDOH2), which kinetically suppress O2 attack by lowering the local electron density at the oxygen center via intramolecular O–H···N═C interactions and extended π-conjugation, as confirmed by density functional theory (DFT) calculations. Consequently, this carbon capture system achieves a release/capture efficiency of 92%, a Coulombic efficiency of 81%, and an energy consumption of 149 kJ mol–1CO2. This work establishes intramolecular hydrogen bonding as a kinetic protection strategy against parasitic O2 oxidation, offering a molecular design principle transferable to other PCET-based electrochemical systems.
Abstract Ultra-long cooling times are the most crucial ingredient for the successful development of a hot-carrier solar cell. Recent experimental reports for metal halide perovskites show the possibility of reaching these relevant values using Sn-based perovskite compositions, due to their low effective mass. In this work, the governing underlying physics is uncovered by investigating the interplay between band filling and the hot phonon bottleneck effect. By using ensemble Monte Carlo simulations and through comparison with time-resolved photoluminescence measurements, it is demonstrated that solely the combination of these two phenomena is sufficient to reproduce ultra-long carrier cooling times. The dependency of band filling on material parameters is analyzed, and it is crucially shown that carriers affected by band filling remain hot in terms of their Fermi–Dirac temperature for the remainder of their energy relaxation period. Our results are important in the discussion regarding the suitability of metal halide perovskites for future HCSC applications, and function as a road-map towards the successful construction of a perovskite-based HCSC.
Abstract All-solid-state lithium batteries (ASSLBs) feature reliable safety, high energy density, and stable cycling, stepping into the key development and application stage. However, a main challenge impeding their further commercialization arises from the complex mechano-(electro)chemical coupling effects at the cathode active material (CAM)/solid-state electrolyte (SSE) interface, which critically governs interfacial contact integrity, ion transport efficiency, and overall cell performance and lifespan. Innovatively, this review decouples and independently analyzes two core degradation pathways: mechanical failure induced by stress accumulation and structural evolution and (electro)chemical degradation driven by space charge layer (SCL) formation, elemental diffusion, and interfacial reactions. Corresponding stabilization strategies are critically evaluated, including strain-mitigating designs such as single-crystal cathodes, near-zero-strain materials, deformable electrolytes, and pressure-adaptive assembly, complemented by (electro)chemical passivation through coating and buffer layers. Ultimately, this work elaborates in detail on the integrated coupling mechanisms, surveys advanced characterization techniques, and proposes future research directions, offering theoretical and methodological guidance for ASSLB development.
Abstract The insufficiently protective cathode electrolyte interphase (CEI) remains a critical challenge for sodium-ion batteries, particularly under wide temperature conditions. Conventional CEI-forming additives rely on potential-driven decomposition during charging, leaving the cathode surface vulnerable before polarization. Here, we develop a dual-driven CEI regulation strategy using N-fluorobenzenesulfonimide (NFSI), integrating contact-driven preformation with potential-driven reinforcement. Upon contact with Na4Fe3(PO4)2P2O7 (NFPP), NFSI induces spontaneous interfacial redox reactions to generate a NaF-rich inner layer, while the intermediate NaNSI is subsequently oxidized to form an N/S-containing outer layer during charging. This bilayer CEI suppresses electrolyte decomposition, transition-metal dissolution, and interfacial degradation while improving Na+ transport. With 1.0 wt % NFSI, NFPP/Na cells retain 79.9% capacity after 500 cycles, compared with 45.8% for the base electrolyte, and maintain cycling capability from –20 to 80 °C. The strategy is further validated in other cathodes and NFPP||HC full cells, providing a programmable approach for durable sodium-ion batteries.
Abstract Zinc–iodine (Zn-I2) batteries are attractive for grid-scale energy storage owing to safety and low cost, yet practical deployment is hindered by shuttling of soluble polyiodide intermediates (I3–, I5–), which causes capacity decay, anode corrosion, and thermal instability. We report a universal electrode design using a microphase-separated gel cathode based on an amphiphilic acrylamide copolymer (a-PAM). The copolymer forms a 3D network with hydrophilic ion-transport channels and embedded nanoscale hydrophobic domains. These domains physically sequester and chemically anchor iodine species, effectively restraining their dissolution and cross-electrode shuttling. The cathode delivers 209.3 mAh g–1 and retains 87.7% of its initial capacity over 15,000 cycles (269 days) at 1 A g–1. It also sustains stable cycling at 80 °C with 80% capacity retention after 500 cycles. This work establishes a generalizable design principle to suppress soluble intermediates, enabling durable and safe aqueous batteries for practical applications.
Abstract Perovskite solar cells (PSCs) have emerged as promising candidates for space photovoltaics, due to their high power-per-weight ratio. However, the space environment imposes harsh requirements, such as radiation tolerance. Especially, proton radiation induces defects in solids, reducing the lifetime of devices. While encapsulation can reduce damage, cover glasses are incompatible with the desirable development of flexible solar cells. Here, a thin-film encapsulation of ALD-AlOx is tested as an outgassing barrier against different space-relevant proton energies, i.e., 0.05, 1, and 3 MeV, with a fixed fluence of 5 × 1012 p+/cm2. While simulations confirm that even low-energy protons can easily overcome the barrier, the encapsulant works by preventing the outgassing of organic components displaced or thermally volatilized by protons. Thus, a detrimental increment of the PbI2 moiety within the perovskite absorber is prevented. The retained performance was improved from as low as 71% (unprotected devices) to as high as 99% (encapsulated).
Abstract Carbazole-derived hole-selective self-assembled monolayer (SAM) contacts are indispensable for high-performance inverted perovskite solar cells. Nevertheless, self-aggregation and molecular desorption of SAM result in a fragile heterogeneous interface, severely hindering device reproducibility and stability. Here, we propose a proton transfer complex-confined strategy to address the interfacial spatial heterogeneity, thereby enhancing the dispersion and adsorption of SAMs. This achieves a multi-site coupling design at the buried interface, effectively preventing interface destabilization by thermal stress. Consequently, a champion efficiency of 26.23% is achieved, with an impressive fill factor (85.64%). These devices resist thermal degradation at 75 °C for 1368 h. Notably, the potential difference change of the target SAMs after thermal degradation at 150 °C is only 5.9 mV, confirming its interfacial chemical stability. The corresponding perovskite film withstands 100 thermal stress cycles (–60 °C ∼ 85 °C). This strategy also achieves higher photovoltaic performance at a lower temperature (240 K).
Abstract Doping spiro-OMeTAD has contributed to the power conversion efficiency (PCE) improvement of perovskite solar cells. Nevertheless, the actual roles of the radical and dopant, and their influence on the hole transport, have not been identified much. Herein, we explore the roles of the radical and dopant in doped spiro-OMeTAD and study their effects on hole transport. In particular, we identify the formation of a percolating ionic network (PIN), driven by cooperative radical-dopant interactions, as a previously unrecognized origin of efficient hole transport in doped spiro-OMeTAD. Moreover, we optimized the dopant design by changing the cation bulkiness to maximize hole transport without co-solvents. Finally, we introduce in situ polymerization of the dopant for fixation of the percolated network to improve morphological stability. As a result, we achieve 25.59% PCE with improved stability, retaining over 90% of its initial efficiency after 1600 h under 85 °C and over 95% after 800 h under 60 ± 10% relative humidity.
Abstract We introduce a process that electrochemically couples CO2 capture and mineralization (CCM) with water electrolysis (WE). Leveraging the exothermicity of CO2 mineralization to sustain a reverse pH gradient, this approach lowers the potential required for WE by up to 0.39 V. Demonstration in a three-chamber reactor yields a steady-state pH gradient of 4.4, enabling WE at an onset of 1.30 V and Faradaic efficiency for CO2 fixation of 93%, corresponding to a net energy cost of < 0.5 kWh (kg CO2)–1. Abundant waste streams, including steel slag and coal ash, serve as CO2 sorbents, resulting in waste valorization to synthetic calcite. Accounting for the value of calcite, estimated H2 production costs are < 1 USD kg–1. Because CO2 fixation exceeds grid emissions for the equivalent electrical energy consumption, this process produces carbon-negative H2 using immediately available electricity. At scale, this process has the potential to mitigate > 500 Mt CO2 emissions annually.
Abstract Eco-friendly tin (Sn)-based perovskites are highly promising for near-infrared light-emitting diodes (PeLEDs), but their electroluminescence performance currently lags behind that of their lead-based counterparts due to unsatisfactory crystallization and severe Sn2+ oxidation. Herein, we demonstrate a progressive optimization strategy to enhance the Sn-based perovskite crystallization by employing a self-assembled monolayer (SAM) of 2PACz:PFNBr as the buried interface and subsequently incorporating isophthalic dihydrazide (IPDH) as a bulk additive. The 2PACz:PFNBr SAM effectively retards rapid crystallization and facilitates controlled nucleation, ensuring high crystal quality of Sn-based perovskite films. Furthermore, the multifunctional IPDH additive improves crystallization uniformity and inhibits Sn2+ oxidation, resulting in homogeneous perovskite films with minimized defect density. Ultimately, the champion device demonstrates a record external quantum efficiency (EQE) of 20.15%, a maximum radiance of 125 W sr–1 m–2, and a stable emission peak at 890 nm, setting a new benchmark for Sn-based near-infrared PeLEDs.
