Advanced Energy Materials

The ambient printing of high‐performance and stable perovskite solar cells (PSCs) is crucial for enabling low‐cost and energy‐efficient industrial fabrication. However, producing high‐quality perovskite films via ambient printing remains challenging due to direct exposure to air, which easily induces additional stacking defects and triggers perovskite degradation compared to films fabricated by traditional spin‐coating under inert conditions. Here, a multiple molecular interaction strategy is introduced to address this challenge by incorporating a 2‐thiazole formamidine hydrochloride (TC) additive, effectively suppressing defect formation during ambient printing. The specific interactions between TC and precursor components, i.e., multiple hydrogen bonds and coordination interactions, could promote the crystallization of α‐phase perovskites and reduce cation and anion vacancies simultaneously when drying in air. These endows high‐quality ambient‐printed perovskite films with large crystalline grains with eliminated nanovoids and low trap‐densities, which improve charge carrier dynamics and prevent perovskite decomposition and hydration under thermal/humidity stress during long‐term annealing/ambient storage. The unencapsulated PSCs show a high efficiency of 23.72% with good stability, i.e., realizing 92% and 95% efficiency retention after 672 h of annealing at 85 °C in a N2 atmosphere and after 2088 h of storage in ambient air.

Nickel‐based double perovskites AA′BB′O6 are an underexplored class of oxygen evolution reaction (OER) catalysts, in which B‐site substitution is used to tune electronic and structural properties. BaSrNiWO6, with a B‐site comprised of alternating Ni and W, exhibits high oxygen evolution activity, attributed to the evolution of a highly OER active surface phase. The redox transformation of Ni²⁺(3d⁸) to Ni³⁺(3d⁷) combined with partial W dissolution into the electrolyte from the linear Ni(3d)‐O(2p)‐W(5d) chains drives an in situ reconstruction of the surface to an amorphized, NiO‐like layer, promoting oxygen redox in the OER mechanism. However, the high valence W⁶⁺(5d⁰) acts as a stabilizing electronic influence in the bulk, preventing the mobilization of lattice oxygen which is bound in highly covalent W─O bonds. It is proposed that the surface generated during the OER can support a lattice oxygen evolution mechanism (LOEM) in which oxygen vacancies are created and preferentially refilled by electrolytic OH⁻, while bulk O species remain stable. This surface LOEM (sLOEM) allows BaSrNiWO6 to retain structural integrity during OER catalysis. With a Tafel slope of 45 mV dec⁻¹ in 0.1 m KOH, BaSrNiWO6 illustrates the potential of Ni‐based double perovskites to offer both OER efficiency and bulk stability in alkaline electrolysis.

The skyrocketing demands for electric vehicles cause large quantities of spent lithium‐ion batteries (LIBs) and pressure on the global supply chain, leading to raw materials shortages and cost increases. In LIBs, LiNixMnyCozO2(NMC) cathodes are one of the major cathode materials. Thus, recycling NMC cathodes from spent lithium‐ion batteries is emerging because they contain abundant valuable materials, which can be considered unique “mineral” sources. Impurities are one of the main concerns for introducing recovered materials back into new battery manufacture because impurities are typically considered to impair the properties of recovered materials. However, some impurities can beneficially act as dopants or coatings. To comprehensively understand the effects of different impurities and treat impurities properly, this review summarizes the origin and species of possible impurities which can be introduced during different pretreatment processes, analyzes the methods to remove impurities, and discusses the effects of impurities on the regeneration process and recovered materials. This work also outlines future perspectives for fundamental research about impurities and relevant challenges of the recycling industry, helps academia and manufacturers to create new impurity standards of recovered cathode materials, and suggests opportunities for achieving a circular economy for the lithium‐ion batteries industry.

With higher energy density and reduced cost, anode‐free battery has attracted great attention from both academic and industry. However, the development of anode‐free batteries is hindered by their poor cycle life due to the continuous irreversible lithium (Li) consumption at the anode side. Here, a surface‐functionalized alloy foil, which can gradually release active lithium to the cell upon cycling, used as the collector for anode‐free batteries is proposed. The alloy foil is prestored with a certain amount of active lithium via a simple wet contacting reaction between the metal foil and liquid lithium source reagent. The prestored lithium amount can be precisely controlled by reagent concentration and contact time. When the foil is used as the anode, its alloyed surface demonstrates a low nucleation barrier for lithium deposition and a more uniform deposition behavior. More importantly, the alloy collector can rationally release active lithium to sustainably compensate for the irreversible Li consumption upon the cycling of a full cell, thus greatly prolonging the cycle life of the anode‐free battery by 10 times. Besides, this technique can be extended to diverse metal collectors demonstrating its broad applicability.

There is a growing interest in fabricated organic material‐based photodiodes (OPDs) since they are lightweight, flexible, and cost‐effective to manufacture. Notably, they exhibit near‐infrared photo‐sensing capabilities that are self‐powered, a feature attributed to the tunable optical properties of organic semiconductor (OSC) materials. Nonetheless, the application of OPDs in the semiconductor industry encounters challenges compared to their inorganic counterparts, such as low sensitivity and limited durability. In this study, a self‐powered OPD using a poly[4,8‐bis(5‐(2‐ethylhexyl)thiophen‐2‐yl)benzo [1,2‐b:4,5‐b′]dithiophene‐2,6‐diyl‐alt‐(4‐(2‐ethylhexyl)‐3‐fluorothieno[3,4‐b]thiophene‐)‐2‐carboxylate‐2‐6‐diyl)]:biaxial active layer of phenyl‐C70‐butyric acid methyl ester (PTB7‐Th:PC70BM) and an organic hole transport layer (HTL) composed of poly(3,4‐ethylenedioxythiophene) and poly(styrene sulfonate) (PPY:PSS) is developed. These results highlight the effectiveness of PPY:PSS as an HTL, demonstrating distinct improvements in efficiency, photosensitivity, photo‐detectivity, and operational stability of the OPD when the weight ratio between the PPY and PSS is 1:2.

Reducing defect density is of significant importance for enhancing the power conversion efficiency (PCE) and stability of perovskite solar cells (PSCs). While most previous outstanding studies have focused on individual layers within the perovskite device structure. Herein, a three‐in‐one strategy using the aminoacetonitrile hydrochloride (AmiHCl) molecule to reduce the defects in the bulk and surface of perovskite. The results of the study found that the AmiHCl bottom modification can decrease the number of buried interface holes, doping into bulk perovskite can modulate crystallization via a strong interaction between AmiHCl and perovskite components, and the upper interface modification can inhibit the formation of vacancies by creating hydrogen bonds with A‐site cations. This approach yields PSCs with an efficiency of 25.90% and a high fill factor (FF) of 88.54%. Additionally, the modified PSCs show significantly enhanced operational stability, with the PCE retaining more than 90.0% of the initial value after 1350 h of maximum power point tracking.

Ionic thermoelectric materials have emerged as a promising avenue for harvesting low‐grade waste heat, with significant potential for applications in wearable electronics. This study introduces a novel design for ionic thermoelectric capacitors (ITECs) by incorporating host–guest complexation between α–cyclodextrin (α‐CD) and triiodide ions (I3⁻). The strong host–guest complexation between α‐CD and I3⁻ confines the diffusion of I3⁻ within the cylindrical cavities of α‐CD, as evidenced by UV–vis spectroscopy and ¹³C‐NMR analysis. This confinement enhances the ion mobility difference between I3⁻ and sodium ions, which in turn significantly boosts the ionic thermopower of the polyvinyl alcohol/α‐CD/NaI hydrogels. Accordingly, the optimized sample achieves an impressive positive ionic thermopower of 14.24 mV K⁻¹ and a high ionic power factor of 477.2 µW K⁻² m⁻¹. Furthermore, the stretchable ITEC demonstrates a substantial power density of 5.9 mW m⁻². When integrated into a 3‐leg device, a stable thermovoltage of 176 mV is generated under a temperature gradient of 4.4 K, thus highlighting the potential of this system for efficient thermal energy harvesting.

Ternary CaAl2Si2‐structure‐type Zintl compounds are promising p‐type counterparts to n‐type Mg3(Sb, Bi)2 for thermoelectric energy conversion. However, many of these p‐type Zintl compounds suffer from low carrier concentration and mobility, resulting in poor thermoelectric performance. Here, it is revealed that their ultralow mobility stems from strong polar optical phonon scattering, and demonstrate that their electrical transport properties can be dramatically boosted by employing a screening effect. By employing isovalent alloying with Cd and Yb, along with Li aliovalent acceptor doping in CaMg2Sb2 to increase carrier concentration and induce a strong screening effect, a significant improvement in carrier mobility and, consequently, the power factor is achieved. Moreover, isovalent alloying weakens chemical bonding, causing the softening and deceleration of both acoustic and optical phonons and, thus, a reduction in lattice thermal conductivity. As a result, a ZT of 1.1 is achieved in the Ca0.69Yb0.3Li0.01Mg1.5Cd0.5Sb2 sample at 773 K, representing a 30‐fold increase compared to the pristine CaMg2Sb2. It is also proposed that the polar coupling constant can serve as a criterion for identifying materials with low intrinsic carrier concentration and mobility but with potential for thermoelectric applications facilitating the development of other thermoelectric materials beyond CaAl2Si2‐structure‐type Zintl compounds.

Photothermal catalysis, a frontier in heterogeneous catalysis, combines light‐driven and thermally enhanced chemical reactions to optimize energy use and reaction efficiencies at catalytic active sites. By leveraging photothermal conversion, this approach links renewable energy sources with industrial chemical processes, offering significant potential for sustainable applications. This review categorizes photothermal catalysis into three types: light‐driven thermocatalysis, thermally enhanced photocatalysis, and photo‐thermo coupling catalysis. Each category is analyzed, emphasizing mechanisms, performance factors, and the role of advanced materials such as plasmonic nanoparticles, semiconductors, and hybrid composites in enhancing light absorption, thermal distribution, and catalytic stability. Key challenges include achieving uniform thermal and photonic energy distributions within catalytic reactors and developing accurate performance evaluation metrics. Applications such as CO₂ reduction, ammonia synthesis, and plastic upcycling highlight the environmental and industrial relevance of this technology. The review identifies limitations and suggests innovations in materials design and energy‐storing mechanisms to enable continuous catalytic processes. Future directions emphasize photothermal catalysis's potential to transform sustainable energy systems and advance green chemical production. This synthesis aims to guide research and foster practical adoption of photothermal technologies at an industrial scale.

Energy‐efficient, safe, and reliable Li‐ion batteries (LIBs) are required for a wide range of applications. The introduction of ultra‐thick graphite anodes, desired for high energy densities, meets limitations in internal electrode transport properties, leading to detrimental consequences. Yet, there is a lack of experimental tools capable of providing a complete view of local processes. Here, a multi‐modal operando measurement approach is introduced, enabling quantitative spatio‐temporal observations of Li concentrations and intercalation phases in ultra‐thick graphite electrodes. Neutron imaging and diffraction concurrently provide correlated multiscale information from the scale of the cell down to the crystallographic scale. In particular, the evolving formation of the solid electrolyte interphase (SEI), observation of gradients in total lithium content, as well as in the formation of ordered LixC6 phases and trapped lithium are mapped throughout the first charge–discharge cycle of the cell. Different lithiation stages co‐exist during charging and discharging; delayed lithiation and delithiation processes are observed in central regions of the electrode, while the SEI formation, potential plating, and dead lithium are predominantly found closer to the interface with the separator. The study emphasizes the potential to investigate Li‐ion diffusion and the kinetics of lithiation phase formation in thick electrodes.

Zinc‐air batteries (ZABs) offer promising forthcoming large‐scale high‐density storage systems and the cost‐effectiveness of electrode materials, specifically in solid‐state and liquid electrolytes. However, the uncontrolled diffusion and utilization of irreversible zinc components and cell design principles limit practical applications with severe capacity fade and interfacial reactions. In this perspective article, the aim is to shed lights on the underlying mechanisms of solid electrolytes and interfaces alongside the current status and prospective research insights. Formulations of ampere‐hour (Ah)‐scale cylindrical/pouch cells are discussed for 100–500 Wh kg⁻¹ cell‐level energy metrics under realistic operations. The electrode/electrolyte interface dynamics, scale‐up readiness, testing protocols, and key performance metrics are also suggested for transforming lab‐scale research into practical production.

Phase transition serves as an ordinary behavior occurring during the high‐temperature calcination process, while it becomes quite complicated in Li‐rich materials composed of rhombohedral phase LiTMO2 (TM: Ni, Mn) with R3¯${\bar{3}}$m space group and monoclinic phase Li2TMO3 with C2/m space group. Yet to be firmly elucidated is how the precursor transforms into LiTMO2 (R3¯${\bar{3}}$m)‐Li2TMO3 (C2/m) compound and what is the precise conversion mechanism between these two phases. This work systematically elaborates the structural evolution with Li/O incorporation during calcination, and proposes a LiTMO2 to Li2TMO3 phase transition mechanism. A series of characterizations on structural rearrangement and detailed analysis provide insights into the comprehension of this transition, i.e., the transition metal (TM) vacancies induced by interlayer TM ions migration function as the primary reason driving the transformation from LiTMO2 to Li2TMO3. This work offers a novel concept for the structural regulation in Li‐rich cathodes.

Sodium‐metal batteries are the most promising low‐cost and high‐energy‐density new energy storage technology. However, the sodium‐metal anode has poor reversibility, which can be optimized by constructing the robust solid electrolyte interphase (SEI). Here, a concept of dual‐weak‐interaction electrolyte (DWIE) is demonstrated, its double‐layer solvation structure is composed of weakly solvated tetrahydrofuran as the inner layer, and dipole interaction are introduced in the outer layer by dibutyl ether. This double‐layer solvation structure dominated by contact ion pairs and aggregates can promote to deriving of inorganic‐rich SEI film, resulting in smooth and dendrite‐free sodium‐metal deposition. By adjusting the molecular configuration of dibutyl ether to diisobutyl ether, the dipole interaction is further enhanced, resulting in stronger weakly solvating effect. Thus, the Na||Cu cells using the optimized DWIE achieved a high Coulombic efficiency of 99.22%, surpassing most electrolyte design strategies. Meanwhile, at 5C, the Na3V2(PO4)3 (NVP)||Na cell achieves stable cycling exceeding 3000 cycles. Even under rigorous conditions of ≈8.8 mg cm⁻² NVP loading and 50 µm thickness Na, the full cell can achieve a long cycling lifespan of 217 cycles. The pioneering concept paves the way for crafting readily achievable, cost‐effective, and eco‐friendly electrolytes tailored for SMBs, and offers potential applications in other battery systems.

Lithium metal anode emerges as an ideal candidate for the next generation of high‐energy‐density batteries. However, challenges persist in achieving high lithium utilization rates while maintaining the demands of high energy density and extended cycle life. In this work, a novel conversion–lithiophilicity strategy is proposed to regulate the longevity of high‐energy‐density batteries by injecting lithium ion activity. This strategy is validated through carbon nanofiber decorated with Fe3C and Fe2O3 particles. The uniform metallic lithium deposition induced by lithiophilic Fe3C substrates has been verified through lithium deposition/stripping experiments and density functional theory calculations. The electrochemical active Fe2O3 component supplies additional anodic capacity and suppress battery degradation, as demonstrated in lithium‐ion storage research and three electrode system studies. When paired with LiFePO4 cathodes at an N/P ratio of 2, the full battery showcases outstanding cycling stability over 300 cycles at 1C, with an exceptional energy density of 438 Wh kg⁻¹ (calculated based on the cathode material and lithium content). Furthermore, the full battery delivers rapid kinetics of 124 mAh g⁻¹ at 2C. The conversion–lithiophilicity strategy presented offers a promising avenue for the development of high‐energy density and long‐life lithium metal batteries.

Heterostructure engineering and active component reconstruction are effective strategies for efficient and rapid charge storage in advanced sodium‐ion batteries (SIBs). Herein, sandwich‐type CoSe2@MXene composites are used as a model to reconstruct new active Cu2Se@MXene heterostructures by in situ electrochemical driving. The MXene core provides interconnected pathways for electron and ion conduction, while also buffering volumetric expansion to stabilize the structure. This reconstructed Cu2Se@MXene heterointerface features abundant sodium storage active sites, enhanced Na⁺ adsorption, and diffusion kinetics, thus increasing sodium storage capacity. Moreover, the elevated Co valence state during the discharge process allows it to act as an electron reservoir to provide additional electron supply for Cu2Se conversion and accelerate the sodium storage kinetics. When employed as an anode in SIBs, the CoSe2@MXene electrode exhibits high capacity (694 mAh g⁻¹ at 0.1 A g⁻¹), excellent rate performance (425 mAh g⁻¹ at 20 A g⁻¹), and exceptional durability (437 mAh g⁻¹ after 10 000 cycles at 5 A g⁻¹ with a 0.0014% capacity decay per cycle). The electrochemical reconstruction and sodium storage mechanism of Cu2Se@MXene anode is further revealed through ex situ characterization and theoretical calculations. This work provides a new approach for designing advanced conversion‐type anodes for SIBs.

Photocatalytic H2O2 synthesis from H2O and O2 is considered to be one of the most promising alternative approaches for manufacturing H2O2. Developing highly active and selective photocatalysts is of significant in achieving efficient H2O2 photosynthesis. Herein, an ethynyl‐linked donor–acceptor covalent organic framework (COF), named EBBT‐COF, is prepared from the condensation reaction between an electron‐deficient unit 4,4′,4″‐(1,3,5‐benzenetriyltri‐2,1‐ethynediyl)tris‐benzenamine and an electron‐rich unit benzo[1,2‐b:3,4‐b′:5,6‐b″]trithiophene‐2,5,8‐tricarboxaldehyde. Powder X‐ray diffraction and N2 adsorption isotherm unveil the crystalline porous hcb network of EBBT‐COF with pores size centered at ca. 2.3 nm. Spectroscopic characterizations demonstrate the excellent visible‐light absorption capacity and enhanced photo‐induced charge separation and transport efficiency of EBBT‐COF owing to its donor–acceptor architecture. Density functional theory calculations and electrochemical tests indicate the high activity and selectivity of EBBT‐COF toward 2e⁻ O2 reduction reaction and 2e⁻ water oxidation reaction with triethynylbenzene and trithiophene moieties to accelerate O2‐to‐H2O2 and H2O‐to‐H2O2 conversion, respectively. These merits enable EBBT‐COF to be a promising photocatalyst toward H2O2 generation from H2O and O2 with a H2O2 yield rate of 5 686 µmol g⁻¹ h⁻¹, an optimal apparent quantum yield of 15.14%, a solar‐to‐chemical conversion efficiency of 1.17% (λ > 400 nm), representing one of the best performance among COF‐based photocatalysts reported thus far.

Colloidal semiconductor nanocrystals (NCs) have garnered significant attention as promising photovoltaic materials due to their tunable optoelectronic properties enabled by surface chemistry. Among them, AgBiS2 NCs stand out as an attractive candidate for solar cell applications due to their environmentally friendly composition, high absorption coefficients, and low‐temperature processability. However, AgBiS2 NC photovoltaics generally exhibit lower power conversion efficiency (PCE) compared to other NC‐based devices, primarily due to numerous surface traps that serve as recombination sites, leading to a short diffusion length for free carriers. To address this challenge, this work develops donor and acceptor blended (D/A) AgBiS2 films. Through ligand modulation, this work formulates acceptor and donor AgBiS2 NC inks with suitable electrical band alignment for charge separation, while ensuring that they are fully miscible in the same solvent. This enabled the fabrication of high‐quality, thickness‐controllable D/A‐blended junction films. This work finds that this approach effectively facilitates carrier separation, leading to an enhanced carrier lifetime and diffusion length. As a result, using this approach, this work achieves AgBiS2 films that are twice as thick in solar cell applications compared to conventional devices, leading to improvements in current density and a solar cell PCE of 8.26%.

Conventional aliovalent doping, which involves replacing host atoms with solute ones, is a well‐established strategy in wet chemical synthesis for enhancing semiconductor performance. However, this method faces serious challenges like low solubility and unavoidable carrier mobility loss, which hinder significant performance improvements, particularly in thermoelectrics. Herein, a novel solvent‐doping strategy is reported that effectively improves the carrier concentration in nanocrystals by stabilizing cation or anion vacancies. Density functional theory calculations and pair distribution function tests reveal that solvent doping increases the atomic ordering and reduces deformation potential, thereby significantly enhancing carrier mobility. Additionally, the conversion of solvent molecules into carbon contributes to further suppressing the lattice thermal conductivity in substrates. As a result, a record‐high peak ZT value of ≈1.0 and a measured thermoelectric conversion efficiency of 1.47% are obtained in solvent‐doped Bi2S3. Similarly, SnS exhibits a remarkable increase of ≈150% in the peak ZT value following solvent doping. This study demonstrates the application of solvent‐doping strategy in thermoelectrics and suggests the potential in other fields, such as transistors, photovoltaic, and catalysis.

Wave energy is a promising sustainable energy yet to be fully exploited due to the low frequency and broad‐banded wave fields, so much so that difficult to capture, resulting in low efficiency and limited power output from current many wave energy harvesters. Here, a topological defect gyro‐multigrid triboelectric nanogenerator (TD‐GM‐TENG) is proposed that harnesses the mechanical energy of ocean waves to generate electricity and promotes the accumulation of triboelectric charge on the basis of realized from low to high rotation speed under the precession and gravitation acceleration effects. It benefited from topological defect strategy, TD‐GM‐TENG offers a charge transfer rate of 3.1 µC s⁻¹ that when can reach to a speed of nearly 1000 rpm at the wave frequency of 1 Hz. Furthermore, the charge density reaches 90 µC m⁻² in a cycle of 0.06 s, which is 1.6 times higher than the same kind of spherical‐TENGs in the field of ocean energy harvesting. Finally, TD‐GM‐TENG unit outputs a peak power of 3.7 mW at the simulated water wave environment of 1 Hz and demonstrates its applicability and feasibility of being used as a distributed emergency power supply in the offshoring observation and early warning services.

The nanoscale mechanisms of ion deintercalation in battery cathode materials remain poorly understood, especially the relationship between crystallographic defects (dislocations, small angle grain boundaries, vacancies, etc), device performance, and durability. In this work, operando scanning X‐ray diffraction microscopy (SXDM) and multi‐crystal X‐ray diffraction (MCXD) are used to investigate microstrain and lattice tilt inhomogeneities inside Li1 − x Ni0.5Mn1.5O4 cathode particles during electrochemical cycling and their influence on the material degradation. Using these techniques, microscale lattice degradation mechanisms are investigated inside single crystals, extend it to an inter‐particle scale, and correlate it with the long‐term degradation of the cathode. During cycling, a crystal lattice deformation is observed, associated with phase transitions and inherent lattice defects in the measured particle. Residual misorientations are observed in the structure even after full discharge, indicating an irreversible structural change of the lattice. However, after long‐term cycling such lattice misorientations together with active material dissolution are further exacerbated only in a subset of particles, suggesting high heterogeneity of degradation mechanisms between the cathode particles. Selective degradation of particles could be caused by varying crystal quality across the sample, highlighting the need for a deep understanding of defect microstructures to enable a more rational design of materials with enhanced durability.

Reversible protonic ceramic cells (r‐PCCs) are highly attractive energy storage and conversion technology, while the insufficient activity of state‐of‐the‐art air electrodes at reduced temperatures strongly limits their practical applications. Herein, this work reports a reduction/re‐oxidation strategy to design a new highly efficient, and durable nanocomposite air electrode for boosting the performance of r‐PCCs operated at intermediate temperatures. Specifically, single‐phase Ba(Co0.4Fe0.4Zr0.1Y0.1)0.9Ni0.1O3‐δ perovskite is selected as the precursor, its treatment in hydrogen atmosphere at 450 °C and then re‐oxidation in air leads to the formation of a nanocomposite, consisted of a perovskite‐based main phase and BaCoO3‐δ and NiO secondary‐phase nanoparticles, where the BaCoO3‐δ phase facilitates oxygen surface exchange while NiO nanoparticles promote surface oxygen/steam adsorption. The corresponding r‐PCC exhibits superior performance at 550 °C in a symmetrical cell (0.162 Ω cm²), a single fuel cell (0.690 W cm⁻²) and an electrolysis cell (−1.066 A cm⁻² at 1.3 V). Such nanocomposite is thermodynamically stable at intermediate temperatures and offers better thermomechanical compatibility with protonic electrolyte because of the reduced thermal expansion coefficient. As a result, superior durability in both fuel and electrolysis cell modes is demonstrated. This study paves a new way for designing outstanding air electrodes for r‐PCCs with great application potential.