All-polymer solar cells (all-PSCs) are of interest owing to their unique advantages, including remarkably improved device stability and exceptional mechanical stretchability. Over recent years, there has been a notable increase in the power conversion efficiency (PCE) of all-PSCs, largely attributed to advancements in the morphology control of the active layer. Notably, the domain size is of paramount importance as it impacts critical factors such as exciton dissociation, charge transport, and collection. However, the low glass transition temperature of conjugated polymers, coupled with a minimal change in mixing entropy, often results in an excessive degree of phase separation. Consequently, it is essential to comprehend the evolution of phase separation and develop strategies to regulate the domain size. In this review, we elucidate the key parameters that contribute to the enhancement of phase separation and present qualitative and quantitative characterization techniques for domain size. Building on this foundation, we introduce the strategies and principles for regulating domain sizes, encompassing factors such as crystallinity, miscibility, and molecular conformation from a thermodynamic perspective, as well as the film-forming kinetics and the crystallization sequence from a kinetic perspective. Lastly, we offer insights into the current challenges and potential future prospects for the evolution of all-PSCs.

For the first time, a printable, miniaturized, and gate-controlled electrochemical capacitor-diode (G-CAPode) is presented. The heart of the device consists of a recently developed asymmetric electrical double-layer capacitor system based on selective, size-dependent ion adsorption. Due to the introduction of a sieving carbon with ultramicroporous pores (d = 0.69 nm) as one electrode material, an effective blocking of ions with sizes below the pore size of the carbon can be achieved, leading to a unidirectional charging comparable to a diode (CAPode). This “working capacitor” (W-Cap) was further expanded by introducing a third (“gate”) electrode enabling a control of the current and voltage output of the W-Cap depending on the applied gate bias between the gate electrode and counter electrode of the W-Cap resembling transistor features. By varying the gate bias voltage, the potentials and therefore the working window of the W-Cap electrodes are shifted to more positive or negative potentials, leading to an increase or decrease of the G-CAPode capacitance. The printed G-CAPode was tested as a switchable device analogous to an I-MOS varactor for the adjustable filtering of AC signals in a high-pass filter and band-pass filter application. This investigation opens the possibility to couple capacitive (energy storage), diodic (current rectification), and transistor (voltage-controlled switching) characteristics in one device and also addresses its process integration via 3D printing.

Understanding and regulating the electronic states of single-atom sites near the Fermi energy level are essential for developing effective electrocatalysts for lithium–oxygen batteries (LOBs). In this study, we introduce an axial oxygen ligand at the metal center of cobalt porphyrin (CoPP) to adjust the electronic state of the Co center. Theoretical calculations and experimental findings show that this axial interaction disrupts the planar tetragonal crystal field of CoPP, resulting in enhanced spin polarization and electronic rearrangement. This rearrangement of d orbitals causes an upward shift in the frontier orbitals, which facilitates electron exchange during reactions. Additionally, the increased number of unpaired electrons in the d orbitals enhances the adsorption of CoPP-O-MXene to various oxygen species, promoting the formation of a thin film-like Li₂O₂. These thin film-like discharge products improve contact with the electrode surfaces, leading to easier decomposition during the charging process. Consequently, CoPP-O-MXene-based LOBs demonstrate a high discharge capacity of 11035 mAh g⁻¹, a low overpotential of 0.76 V, and remarkable cycling stability (445 cycles).

In organic solar cells (OSCs), typical methods for fabricating the ternary active layer are blend-casting (BC) or two-step sequential processing (SqP-2T), where all three or at least two components are blended together, which affect the crystallization/aggregation behavior of each other during solid-film formation. Herein, we introduce for the first time a novel three-step sequential processing method, termed SqP-3T, which utilizes hydrocarbon solvents to prepare high-quality ternary active layers. Compared to the SqP-2T and BC techniques, SqP-3T yields an active layer with a higher acceptor ratio on its upper surface and exhibits a longer crystal coherence length in the out-of-plane direction (21.42 Å). These characteristics enhance charge transport and collection. Additionally, SqP-3T devices demonstrate nearly a twofold increase in the transient photovoltage decay constant (up to 2.82 µs) that is related to carrier lifetime to a certain extent, leading to reduced recombination losses. Consequently, the SqP-3T device achieves a high fill factor (75.67%) and a high short-circuit current density (27.35 mA/cm²), contributing to a power conversion efficiency of 19.2%. These results highlight the potential of SqP-3T or a multi-step sequential deposition process in the production of ternary or multicomponent OSCs, which could be adopted by more material systems in the future.

Metal organic frameworks (MOFs) have a promising perspective as oxygen evolution reaction (OER) electrocatalysts due to their high surface areas and tunable structures. However, one of the main challenges for their further application is inferior stability during alkaline OER. Herein, operando x-ray absorption spectroscopy and operando x-ray diffraction of NiCo-MOF-74 materials unveil their electrochemical transformations differentiating between electrolyte-induced, beam-induced, and electrochemically induced changes of the electronic state and local structure around the transition metal centers in addition to their overall crystal structure. An inferior electrolyte- and beam stability of Co-MOF-74 is revealed in comparison to a more stable performance of Ni-MOF-74 and Ni_0.25Co_0.75-MOF-74. Based on the operando measurement results, good experimental practices for future MOF OER electrocatalyst studies are presented.

Overall seawater splitting driven by regenerable electricity is an ideal pathway for mass production of green hydrogen. Nonetheless, its anodic oxygen evolution half-reaction (OER) confronts sluggish kinetics, competitive chlorine evolution, and chloride corrosion or poisoning problems, needing to develop high-efficient and robust electrocatalysts toward those challenges. Herein, novel defect-rich single-phase (NiCoMnCrFe)₃O₄ high-entropy spinel oxide (HEO) is fabricated by low-temperature annealing of high-entropy layered double hydroxide precursor. Due to the presence of abundant defects, unique “cocktail” effect, and efficient electronic structure regulation, such (NiCoMnCrFe)₃O₄ can deliver 500 mA cm⁻² current density at the overpotentials of 268/384 mV in alkaline freshwater/seawater, outperforming its counterparts, commercial IrO₂, and most reported OER catalysts. Moreover, it manifests exceptional OER durability and anticorrosion capability. Theoretical calculations reveal that the e_g occupancies of surface Mn atoms are closer to 1.0, which may be the activity origin of such HEO. Importantly, the constructed (NiCoMnCrFe)₃O₄||Pt/C electrolyzer only requires 1.57 V cell voltage for driving overall seawater splitting to reach 500 mA cm⁻² current under real industrial conditions. This work may spur the development of advanced OER electrocatalysts by combining entropy and defect engineering and accelerate their applications in seawater splitting, metal–air batteries, or marine biomass electrocatalytic conversion fields.

Sandwiched composites with a combination of electromagnetic interference (EMI) shielding performance, thermal conductivity, and electrical insulation show significant potential in electronic packaging. However, the fabrication of such composites using high-performance thermosets as matrices presents challenges due to their permanently crosslinked structures. Here, we relied on the dynamic covalent chemistry to propose an innovative interface-welding strategy to fabricate a sandwiched thermoset (covalent adaptable network)/carbon nanotubes/boron nitride (CAN/CNTs/BN) composite. To sustainability, the CAN matrix was derived from renewable biobased resources, such as vanillin, glycerol triglycidyl ether, and 1,10-diaminodecane. The incorporation of CAN/BN composites as the outer layers bolstered thermal conductivity while maintaining electrical insulation, while the CAN/CNTs interlayer efficiently attenuated electromagnetic waves. With a BN and CNT content of 30 wt%, the CAN/CNTs/BN composite achieved a thermal conductivity of 1.79 W·m⁻¹·K⁻¹, an EMI shielding effectiveness exceeding 55 dB in the X-band, and an ultra-low electrical conductivity of 1.6×10⁻¹³ S·m⁻¹. Leveraging dynamic covalent chemistry, the interface-welding technique fostered fully integrated interfaces, ensuring superior mechanical properties of CAN/CNTs/BN composite including a tensile modulus of 3837.8 ± 196.9 MPa and tensile strength of 62.1 ± 3.7 MPa. Additionally, its exceptional heat dissipation performance positions CAN/CNTs/BN composite as a promising contender for electronic packaging applications.

Tin sulfide (SnS₂) is a promising anode material for sodium/potassium-ion batteries (SIBs/PIBs) due to its large interlayer spacing and high theoretical capacity. However, its application is hindered by sluggish kinetics, volume expansion, and low conductivity. In this work, a synergistic engineering route is proposed that combining environmentally friendly chlorella with sulfurized polyacrylonitrile (SPAN) to achieve green doping and dual-mode confinement SnS₂-based anode. The SPAN matrix prevents SnS₂ agglomeration, enhances charge transfer, and improves structural stability, while phosphorus (P) doping accelerates “solid‒solid” conversion kinetics. The SnS₂‒P‒SPAN anode demonstrates outstanding sodium/potassium storage performance across a wide temperature range (‒40°C to 70°C), delivering high reversible capacities, excellent rate capability, and exceptional long-term cycling stability. The reliability of the as-developed strategy in a SnS₂‒P‒SPAN//NaNi_0.4Fe_0.2Mn_0.4O₂ full cell is also verified, which shows strong practical potential with high capacity and long durability (241 mAh g⁻¹/800 cycles/0.5 A g⁻¹/25°C; 159 mAh g⁻¹/400 cycles/0.5 A g⁻¹/60°C; 105 mAh g⁻¹/800 cycles/0.5 A g⁻¹/‒15°C). The associated electrochemical mechanisms of SnS₂‒P‒SPAN are elucidated through comprehensive electrochemical tests, in/ex situ analyses. The theoretical calculation unveil that P-doping helps to enhance the adsorption capacity of the Na⁺ and discharge products. This work may pave the way for developing promising yet imperfect electrode materials in the field of energy storage.

Constructing an interlayer between perovskite and zinc oxide (ZnO) electron transporting layer to passivate the implacable interfacial defects for upgrading the efficiency and stability of flexible perovskite solar cells (f-PSC) is a daunting challenge and remains under explored. Herein, we present a cascade bridge interlayer strategy of zeolitic imidazole framework-8 (ZIF-8) at the ZnO/perovskite interface. The ZIF-8 interlayer uplifts the work function, creating a cascade pathway and bridges through nitrogen bonding with Pb²⁺ ions of perovskite, thereby facilitating electron transport and reducing interfacial charge recombination. Consequently, the ZnO surface defects are passivated by alleviating the OH^‒ species, and thus the device stability is significantly improved. The f-PSC with ZIF-8 interlayer delivers a stable conversion efficiency of 17.10% with minimal hysteresis. By utilizing the piezo-phototronic effect and subjecting the f-PSC to a tensile strain of 1.6%, a stable efficiency of 18.47% was achieved, representing one of the highest reported efficiencies for ZnO nanorods-based f-PSC. Furthermore, the ZnO‒ZIF-8 exhibits high adsorption capacity toward lead and traps the mobile Pb²⁺ ions at the ZnO/perovskite interface, preventing the negative impact of lead leaching on environmental sustainability.

Perovskite-inspired materials (PIMs) have been investigated as alternatives to organic lead halide perovskites in order to explore novel lead-free materials for photovoltaics. This review describes the structural and optoelectronic properties of PIMs including double perovskites, chalcohalides, rudorffites, bismuth halides, and defect-ordered A₃B₂X₉. Efforts have been recently made to overcome high carrier effective mass, non-radiative recombination, and large bandgaps of PIMs, limiting the photovoltaic performance of PIM-based solar cells. By analyzing the basis for the inferior performance observed by the PIMs, we propose strategies for enhancing the PIM-based solar cells in terms of engineering bulk light-absorbing PIM layers and their interfaces in order to provide insights into the design of future photovoltaic materials.