ACS Applied Energy Materials最新文献

The limited availability of solid electrolytes that simultaneously exhibit high ionic conductivity and robust interface compatibility is acknowledged as a critical barrier to the practical implementation of all-solid-state potassium-ion batteries. In this study, three potassium carbolide isomers and their coordinated complexes were designed and fabricated to enhance the potassium ion conductivity through employing the synergy of heteroatom (nitrogen) and neutral ligand coordination effects. Among them, the new crystal structures of β-potassium carbolide (β-KNCZ for short) and its tetrahydrofuran (THF) complex (β-KNCZ-1.0THF for short) were successfully determined. Upon modulating the position of the nitrogen atom and the content of ligand THF, β-KNCZ-0.75THF exhibited an ionic conductivity of 0.22 mS cm^–1 at 60 °C with an activation energy of as low as 0.19 eV, indicating its potential as a competitive ion conductor. Further optimizing the type and content of ligand, β-KNCZ-0.70EDA (EDA: ethylenediamine) achieved an ionic conductivity of 1.3 mS cm^–1 at 100 °C, which exhibits exceptional performance under the elevated temperature conditions (Table S1). Furthermore, both β-KNCZ-0.75THF and β-KNCZ-0.70EDA demonstrated favorable stability and interface compatibility with a K₂S electrode during hundred hours electrochemical cycles with a low overpotential.

Chirality-induced spin selectivity (CISS) enables spin-selective electron transport without ferromagnetic materials and external magnetic fields. While previous studies have demonstrated CISS-induced modulation of O₂ and H₂O₂ formation during water oxidation, its influence on the one-electron pathway leading to •OH formation remains unexplored. Here, chiral-molecule-modified BiVO₄ photoelectrodes were employed to investigate spin-dependent •OH generation during water oxidation. Quantitative fluorescence measurements reveal a 3.5–4.6-fold enhancement in •OH production on interfaces relative to racemic controls, accompanied by suppressed H₂O₂ formation and enhanced photoelectrochemical performance. Transient absorption spectroscopy confirms the CISS effect, which has been shown to involve a metastable, long-lived charge-trapped state at a semiconductor/chiral molecule interface. The pronounced increase in •OH generation demonstrates that spin polarization can influence not only final reaction products but also transient reactive intermediates. This insight expands the scope of CISS-enabled catalysis and highlights the potential of chiral interfacial engineering to enhance charge-transfer efficiency and photocatalytic performance.

A poly(ionic liquid)-based solid polymer electrolyte (PIL-SPE) was designed to achieve high ionic conductivity, reduced interfacial resistance, and improved compatibility with lithium metal through the suppression of dendritic growth. An electrolyte was synthesized from 1-vinyl-3-(2-benzoyl-ethyl) imidazolium bis(trifluoromethanesulfonyl)imide (VBEIm-TFSI), cross-linked with vinyl ethylene carbonate (VEC), and incorporated with LiTFSI as the lithium salt and lithium difluoro (oxalate)borate (LiDFOB) as an interfacial stabilizer, with polymerization initiated by azobisisobutyronitrile (AIBN) via in-situ thermal polymerization. The in-situ polymerization forms a conformal and stable electrolyte–electrode interface, enabling uniform salt distribution and low interfacial impedance. The resulting PIL-SPE exhibits ionic conductivities of 4.0 × 10^–4 S cm^–1 at 30 °C and 1.04 × 10^–3 S cm^–1 at 70 °C, a lithium-ion transference number of 0.52, and an electrochemical stability window of up to 4.8 V. Symmetric Li cells demonstrate stable plating/stripping over 1000 h at 0.1 mA cm^–2. In LFP|PIL-SPE|Li cells, the electrolyte delivers 100 mAh g^–1 at 1 C for 1000 h with an average Coulombic efficiency of 99.5%. These results demonstrate that the PIL-SPE is a promising candidate for next-generation solid-state lithium metal batteries (lithium-ion batteries, LIBs).

To address the issues of insufficient conductivity, slow reaction kinetics, and limited cycling stability associated with pure MnO₂ electrode materials, this study used MnO₂ as a precursor to prepare MnO₂/Mn₃O₄ composite electrode materials through a subsequent compositing process and investigated their supercapacitor performance. The results show that M2@M4-30, prepared with an optimized reaction time, exhibits the best electrochemical performance, with a specific capacitance of 212.5 F g^–1 at 0.2 A g^–1 and 175.0 F g^–1 at 10 A g^–1, corresponding to a capacitance retention of approximately 82.4%. After 10,000 cycles, the electrode retained 92.86% of its initial capacitance. The performance enhancement is primarily attributed to the dotted loading of Mn₃O₄ on the MnO₂ surface, the formation of the MnO₂/Mn₃O₄ heterointerface, and the multivalent environment of Mn²⁺, Mn³⁺, and Mn⁴⁺. Specifically, the dotted loading structure helps keep the active areas exposed, the heterointerface promotes interfacial charge transfer, and the multivalent Mn states endow the composite system with richer reversible redox activity. The assembled M2@M4-30//AC asymmetric supercapacitor achieves an energy density of 31.6 Wh kg^–1 at a power density of 180.0 W kg^–1, demonstrating significant application potential.

Electrochemical energy conversion and storage technologies such as fuel cells, electrolyzers, and batteries are increasingly limited by the transport of reactants, products, charge, and heat through porous structures. While advances in catalysts and materials have significantly improved device performance, porous media have largely remained stochastic in nature, with transport properties emerging as consequences of fabrication rather than deliberate design. Recent developments in advanced manufacturing, characterization, and computational optimization are enabling the creation of architected porous media with increasingly controllable transport behavior. In this perspective, we introduce a ”transport-by-design” framework in which effective transport properties, including diffusivity, permeability, conductivity, and capillary transport, as well as electrochemically active surface area in reactive porous media, become explicit design targets rather than emergent outcomes. We discuss how architected porous media can provide enhanced control over these properties through graded, hierarchical, anisotropic, and topology-optimized structures and highlight emerging opportunities across electrochemical devices. We argue that designing porous architectures from targeted transport requirements represents an emerging shift from material-centric approaches toward transport-informed engineering as a guiding principle for next-generation electrochemical energy conversion and storage technologies.

Aluminum–graphite (Al–G) batteries suffer from severe self-discharge, with capacity losses of up to 26% within 12 h in conventional chloroaluminate ionic liquid electrolytes. In the Al–G system, self-discharge manifests as the spontaneous deintercalation of AlCl^–₄ anions from the graphite cathode and is further accelerated by parasitic reactions involving the electrolyte, binder, separator, and current collector. Here, we demonstrate a PAN-based polymer electrolyte that simultaneously functions as ion conductor, separator, and cathode binder, thereby suppressing multiple self-discharge pathways at once. The dense polymer matrix kinetically hinders anion deintercalation while eliminating additional binders and porous separators that may promote parasitic reactions. As a result, the system retains 99.5% capacity after 24 h, 97.7% after 7 days, and 94.3% after 21 days under open-circuit conditions, corresponding to a capacity loss of only 0.27% per day. The suppression of self-discharge is primarily attributed to the polymer electrolyte binder, as confirmed by controlled comparisons using an identical current collector across different binder systems. These results were achieved using a commercially available conductive polyimide current collector instead of glassy carbon collectors, which are typically employed in low-self-discharge Al–G systems. This represents an additional advantage for large-scale manufacturability. The proposed multifunctional polymer approach therefore provides a practical route toward aluminum batteries with substantially improved storage stability and enhanced suitability for long-term stationary energy storage applications.

Perovskite solar cells (PSCs) have achieved rapid gains in power conversion efficiency (PCE), yet their broader deployment remains limited by insufficient stability and Pb-leakage concerns. Anthraquinone-based materials are attractive interfacial modifiers, with their carbonyl groups providing Lewis-base sites for passivating undercoordinated Pb-related defects and potential binding sites for Pb immobilization, their π-conjugated aromatic structures facilitating interfacial charge transport, and their redox-active quinone moieties helping suppress degradation-related Pb and iodine species. However, these materials have predominantly been explored as small-molecule additives or interfacial passivators, while their use as polymeric antisolvent additives and the influence of polymer structural characteristics on perovskite properties remain largely unexplored. Herein, we synthesized poly(anthraquinonyl sulfides) (PAQxS), in which anthraquinone units are connected by sulfur-containing linkages that provide conformational freedom and potential soft-donor functionality, and investigated their application as antisolvent additives for PSCs. To examine how these linkage characteristics affect polymer–perovskite interactions, we compared two representative polymers, PAQdS and PAQnS, with relatively shorter and longer sulfur-linkage distributions, respectively. Compared with PAQdS, PAQnS promoted more ordered perovskite crystallization and improved film morphology, accompanied by lower trap density, reduced defect-related carrier losses, and improved charge-carrier behavior. These improvements in film and interfacial properties were associated with an approximately 20% relative increase in PCE, together with a markedly prolonged T₈₀ lifetime and an approximately 40% reduction in Pb leakage. Overall, this study demonstrates the potential of sulfur-linked anthraquinone-based polymers as a structure-guided platform for improving photovoltaic performance, stability, and Pb-leakage mitigation in PSCs while providing insight into structure-dependent film and interfacial behavior.

Kinked polyphenylenes, poly(meta, meta, para-phenylene) (PmmpP), with ethylene oxide (EO) side chains are used as solid polymer electrolytes (SPEs) for Li⁺ conduction. The meta-kinks in P(EO-mmpP) effectively suppress side-chain crystallization and enhance backbone flexibility, resulting in amorphous materials with outstanding ductility and tunable toughness. Varying the EO chain length from three to five units enables tuning of the glass transition temperature (T_g), mechanical properties, and ionic conductivity. Dynamic mechanical thermal analysis reveals two transitions for the side and main chains. While the temperature of side-chain relaxation is independent of side-chain length, the temperature of main-chain relaxation, which is closely related to T_g, decreases with increasing side-chain length. The SPEs exhibit excellent miscibility with LiTFSI upon simple kneading, forming transparent, flexible, and free-standing films. Ionic conductivities increase with increasing side-chain length following Arrhenius behavior. The activation energies (E_A) decrease with increasing side-chain length. However, the E_A of local Li⁺ dynamics from temperature-dependent ⁷Li NMR measurements increases with increasing EO side-chain length due to stronger complexation. As a result, the T_g is dominating local effects of local Li⁺ dynamics and thus governs bulk ionic conductivity. This effect is further enhanced by external plasticization, furnishing a conductivity of 0.483 mS/cm at 80 °C.

Thermochemical energy storage by utilizing concentrated solar power through high-temperature processes requires redox materials with high energy density and good structure stability throughout multiple cycles. In this research, chemical tuning of the calcium chromate series of materials, Ca_1–xSr_xCrO₄, has been conducted to improve the thermodynamics and structure stability of the redox reaction. Structural analysis shows that the structure evolves from a zircon to a monazite type of structure for x ≥ 0.4. It significantly alters the redox reaction mechanism. While CaCrO₄ has a multistep redox reaction with low reversibility, and severe sintering is observed for SrCrO₄, a single-step redox reaction with improved oxygen exchange is observed for intermediate compositions. The optimal composition has a high energy density of ∼ 1.06 MJ/kg, an excellent cycling stability with 99.8% reversibility over 20 cycles, and small thermomechanical losses. The XPS measurements reveal reversible Cr valence states associated with the formation of oxygen vacancies. DFT + U and ab initio molecular dynamics calculations identify the composition at x = 0.6 as the most promising candidate, combining a favorable electronic structure with enhanced oxygen mobility. MSD and diffusion analysis show that oxygen migration is fast and activation energy is low (0.29 eV), which emphasizes the significance of chromate lattice engineering in developing TCES materials for future use.

Photoelectrochemical (PEC) water splitting for renewable fuel production has recently witnessed remarkable progress. Organic semiconductor photoanodes stand at the forefront due to their numerous advantages, such as a wide absorption coefficient, tunable energy levels, and solution processability. However, their stability remains a significant challenge. This study investigates the influence of an eco-friendly hole transport layer, polydopamine (PDA), transferred ex situ onto an organic-based photoanode as a passivating layer. We leverage PDA's unique electrochemical properties as a green and versatile polymer to enhance the stability of the photoanode. Electrochemical tests show that simple ex situ transfer of PDA onto the photoanode surface increases the photocurrent tenfold, reduces the charge transfer resistance from 4.2 to 1.8 kΩ (in the dark) and from 3.5 to 0.4 kΩ (under illumination), while the estimated Fermi energy level shifts by –0.14 eV. These findings support the use of ex situ-transferred PDA as a multifunctional interfacial layer capable of improving charge extraction and photoelectrode stability in organic photoelectrochemical water-splitting systems.