In order to obtain naphthalimide-based polymer cathode materials with high discharge voltage, two conjugated polymers PNIT-Th and PNIT-DTh were designed and synthesized using naphthalimide-thiophene (NI-Th) or naphthalimide-dithiophene (NI-DTh) as the electrochemically active backbone and 2,2,6,6-tetramethylpiperi-dine-1-oxo radical (TEMPO) units with high redox potential as N-position substituents. As expected, the average discharge voltages of PNIT-Th and PNIT-DTh are both relatively high, at 3.12 V (vs Li/Li+) and 3.20 V (vs Li/Li+), respectively, which are higher than the N-alkyl-substituted polymer PNI-DTh (2.35 V (vs Li/Li+)). Benefiting from the electroactive main chain and side groups, PNIT-Th and PNIT-DTh both exhibited high initial discharge specific capacities at 0.1C, with 222.2 mAh g-1 and 240.5 mAh g-1, respectively. The high discharge voltage and discharge specific capacities of the two polymers result in high energy density. At 0.1C, the specific energy densities of PNIT-Th and PNIT-DTh are 711.2 Wh kg-1 and 794.6 Wh kg-1, respectively. It is satisfactory that these two polymers also exhibit excellent long-cycle and rate performance. At 5C, the capacity retention rate remained above 90% after 4000 cycles. The experimental results indicate that polymers containing TEMPO groups are a class of potential cathode materials for lithium-ion batteries.

The development of low-potential plateau capacity in hard carbon (HC) negative electrodes is a key route toward enhancing the energy density of sodium-ion batteries. However, owing to the intrinsic structural complexity of HC, the microstructural origin of sodium storage in the low-potential region remains elusive. Here, a direct correlation between microstructure and electrochemical behavior is established, revealing that sodium storage proceeds via the formation of quasi-metallic Na+ clusters accommodated within closed pores and regulated by surface mesoporous architectures, thereby resolving longstanding mechanistic ambiguities associated with the low-potential plateau. In contrast, microporous-dominated surfaces fail to effectively activate plateau capacity, whereas mesoporous-dominated structures construct efficient Na+ diffusion pathways that enable rapid access to closed-pore storage sites. As a result, the plateau capacity is enhanced by 82.5% relative to microporous structures, accompanied by a pronounced increase in the initial discharge capacity from 168.4 to 347.7 mAh g-1. In situ electrochemical impedance spectroscopy combined with relaxation time distribution analysis further confirms the irreversible evolution of the solid electrolyte interphase and its role in stabilizing interfacial kinetics. Moreover, in situ Raman spectroscopy, integrated with multimodal structural characterizations, unambiguously verifies a multistep "adsorption-intercalation/filling" sodium storage mechanism. This work provides fundamental insights into the role of surface pore structures in HC, thereby guiding the rational design of high-performance HC negative electrodes.

Hard carbon (HC) is a promising anode material for sodium-ion batteries (SIBs). However, how distinct microstructures determine the trade-off between energy density and power density remains poorly understood because of the structural complexity of HC. Here, we propose a molecular rigidity engineering strategy based on polyimide (PI) precursors to establish clear microstructure–performance correlations. By tuning precursor backbone rigidity, flexible PIs preferentially evolve into closed pore dominated structures, whereas rigid PIs promote the synergistic integration of closed pores and graphite-like domains, which simultaneously preserves Na+ storage capacity and accelerates charge transport. The optimized HC derived from the rigid precursor delivers a reversible capacity of 288.9 mAh g−1 at 50 mA g−1 with a high initial Coulombic efficiency of 89.3%. Even at a practical mass loading of 8.08 mg cm−2, the half-cell delivers a practical areal capacity of 1.88 mAh cm−2. Moreover, the corresponding full cell exhibits excellent rate capability and cycling stability. In-situ Raman spectroscopy and in-situ X-ray diffraction reveal an “adsorption → adsorption/filling → intercalation/filling” Na+ storage mechanism. This work provides mechanistic insights into sodium storage in HC and establishes a molecular design strategy for high-performance SIB anodes.

The "shuttle effect" and lithium dendrite issues in lithium-sulfur batteries (LSBs) are the two primary problems that jeopardize their cycle stability and safety. To address these issues, we propose a N,O dual-doped carbon network derived from polyimide and grown directly on carbon cloth (NOCC), synthesized via an in-situ imidization followed by carbonization process. The NOCC is employed as hosts for both sulfur cathodes and lithium metal anodes for high-performance LSBs. On the one hand, the interconnected carbon matrix doped with N and O elements provides enhanced electronic and ionic pathways, while also exhibiting strong interactions with lithium polysulfides (LiPSs). Additionally, the material delivers high catalytic activity for sulfur redox reactions, effectively mitigating the "shuttle effect". On the other hand, the doped heteroatoms increase the lithium affinity of the carbon skeleton, facilitating uniform lithium nucleation and suppressing dendrite growth on lithium metal surfaces. Consequently, the composite cathodes with NOCC as host materials demonstrate an initial discharge capacity of up to 1577 mA h g-1 at 0.2C, an outstanding rate capability with 795 mA h g-1 at 5C, and an impressive long-term cycling stability at 2C for 1000 cycles, maintaining a satisfactory discharge capacity of 411 mA h g-1 with a decay rate of 0.050 % per cycle. When NOCC host is introduced in lithium metal anodes, the composite anodes maintain stable cycling for over 1000 h at 3 mA cm-2. Notably, the NOCC-800-S||NOCC-800-Li full cells achieve remarkable durability, retaining stability at 5C over 1100 cycles. Such innovative carbon-based host material offers a promising approach for improving LSBs' cycling stability and safety, Contributing to their practical commericializtion.

Organic solar cells (OSCs) with efficiencies over 20 % demonstrate significant potential in the photovoltaic market. However, the fabrication of state-of-the-art OSCs often relies on the use of highly toxic solvents. To advance OSCs toward industrial production, it is crucial to develop efficient and environmentally friendly solvent-processed OSCs. In this contribution, 1,2,3-benzothiadiazole is used as a third monomer to modify the benchmark donor D18, affording three terpolymers: PiBTX (X = 10, 20, 30). Thanks to the steric hindrance introduced by 1,2,3-benzothiadiazole, the PiBTX terpolymers exhibit good solubility in the non-halogenated solvent o-xylene and high luminous efficiency. Moreover, the PiBTX terpolymers enable the modulation of multiple properties, including reduced HOMO energy levels, increased J-aggregation in both solution and film, and improved miscibility with the acceptor. Hence, the terpolymers PiBTX outperform D18 in o-xylene-processed OSCs. Notably, owing to efficient charge generation, transport, and extraction, leading to higher JSC and FF, as well as the lower-lying HOMO energy level and potential Forster resonance energy transfer that reduce nonradiative recombination loss, the PiBT20 terpolymer achieves an impressive efficiency of 19.2 %, ranking among the highest for OSCs processed with green solvents. This work offers a robust strategy for designing efficient polymer donors that are compatible with green solvents.

Lithium-sulfur batteries (LSBs) have become a focal point in the electrochemical energy storage research due to their outstanding theoretical capacity of 1675 mA h g- 1 and impressive energy density of 2600 W h kg- 1. Nevertheless, the commercial exploitation of LSBs faces several obstacles, especially the shuttle effect caused by lithium polysulfides (LiPSs) and their sluggish electrochemical reaction rates. With the goal of overcoming these obstacles, a novel polyimide-derived nitrogen and oxygen co-doped nanoflakes decorated carbon cloth (NOCC) has been developed via an in-situ imidization and carbonization strategy to fabricate flexible self-supported cathodes for high-performance LSBs. The interlinked carbon fiber framework of the NOCC endows the sulfur host with excellent electronic conductivity. Simultaneously, the N, O co-doped nanoflakes embedded on the carbon fiber skeleton possess strong chemical adsorption of LiPSs and excellent electrocatalytic efficiency for LiPSs redox owing to the abundant polar nitrogen and oxygen groups. Additionally, the porous structured NOCC promotes rapid lithium-ion transport and physically restricts the spread of LiPSs. Consequently, the NOCC as a sulfur host (NOCC@S), with sulfur content of 1.5 mg cm- 2, exhibits an initial discharge capacity as high as 1661 mA h g- 1 (almost reaching the theoretical value) at a discharge rate of 0.2C. Furthermore, these cathodes exhibit superb rate capabilities, maintaining a discharge capacity of approximately 538 mA h g- 1 at 5C. Impressively, after 700 cycles at a higher rate of 2C, they retain a satisfactory discharge capacity of 485 mA h g- 1, highlighting their robust cycling stability. This new material aims to fabricate flexible, self-supported cathodes for highperformance LSBs, providing a potential breakthrough in commercialization of these batteries.

Excited-state intramolecular proton transfer (ESIPT) molecules has been using as a variety of functionalityled molecular systems. To investigate the relationship between the electron-donor substitution and luminescent properties of ESIPT luminogens, four 2-(2-hydroxyphenyl) benzothiazole derivatives with donor-π-acceptor (D-π-A)-structured were synthesized. The distinct fluorescence properties of them were found to be highly dependent on the electron-donor moiety (triphenylamine and anthracenyl), its substituent position (para and meta position) and solvent polarity. The M-TPA, P-En, and M-En showed ESIPT emission in organic solvents, while the P-TPA showed intramolecular charge transfer process (ICT) emission. It is due to the synergistic effect of the aggregation-induced emission (AIE) and ESIPT, that M-TPA and M-En exhibited high solid-state quantum yields and large Stokes shifts. They were used as a probe for detecting F-, which resulted in rapid colorimetric, high sensitivity and good selectivity. The M-TPA was a turn-on fluorescent probe, which had the best detection property, and the limit of detection was as low as 11 nM. Because M-TPA displayed phenol anion emission in DMSO and F- causes the deprotonation of the M-TPA, which led to significant red shift of the absorption band and enhancement of fluorescence emission. This work provides a reliable strategy for designing high-performance fluorescent sensor via ESIPT manipulation.

In this work, full-color and stable white organic afterglow materials with outstanding water, organic solvents, and temperature resistances have been developed for the first time by embedding the selected polycyclic aromatic hydrocarbons into melamine-formaldehyde polymer via solution polymerization. The afterglow quantum yields and lifetimes of the resulting polymer films were up to 22.7 % and 4.83 s, respectively, under ambient conditions. For the coronene-doped sample, its afterglow color could be linearly tuned between yellow and blue by adjusting the temperature, and it could still emit an intense blue afterglow with a lifetime of 0.68 s at 440 K. Moreover, the films showed a bright and stable white afterglow at 370 K with a lifetime of 2.80 s and maintained an excellent afterglow performance after soaking in water and organic solvents for more than 150 days. In addition, the application potential of the polymer films in information encryption and anti-counterfeiting was also demonstrated.

High-quality conjugated microporous polymer (CMP) films with orientation and controlled structure are extremely desired for applications. Here, we report the effective construction of CMP 3D composite films (pZn/PTPCz) with a controlled porosity structure and preferred orientation using the template-assisted electropolymerization (EP) approach for the first time. The structure of pZn/PTPCz composite thin films and nitrophenol sensing performance were thoroughly studied. When compared to the control CMP film made on flat indium tin oxide (ITO) substrates, the as-prepared pZn/PTPCz composite films showed significantly enhanced fluorescent intensity and much better sensing performance for the model explosive. This was attributed to the metal-enhanced fluorescence (MEF) of porous nanostructured zinc (pZn) and the additional macroporosity of the pZn/PTPCz composite films. This work provides a feasible approach for creating oriented 3D CMP-based thin films for advanced applications. This work provides the effective construction of CMP 3D composite films (pZn/PTPCz) with a controlled porosity structure and preferred orientation using the template-assisted electropolymerization (EP) approach for the first time. When compared to the control CMP film made on flat substrates, the as-prepared pZn/PTPCz composite films showed significantly enhanced fluorescent intensity and much better sensing performance for the model explosive. image

The thermal stability of zeolitic imidazolate framework-8 (ZIF-8) for poly(vinyl chloride) (PVC) has received attention, but its thermal stabilization mechanism needs further clarification. Herein, the stearic acid-modified ZIF-8 with high specific surface area and large pore volume was effectively synthesized by using zinc stearate as the zinc source for the first time. Modification of stearic acid results in larger adsorption capacity of ZIF-8 for HCl and better thermal stability effect for PVC, especially long-term thermal stability. Moreover, the thermal stability mechanism of ZIF-8 for PVC was demonstrated by experiments and theoretical calculations. In addition to absorbing HCl to eliminate autocatalytic degradation of PVC, ZIF-8 disintegrates and may form 2-methylimidazole-Zn-Cl salt complex instead of free ZnCl2, avoiding the negative zinc burning effect. Furthermore, the Diels-Alder reaction between imidazole ring and degraded PVC prevents the extension of the conjugated double bonds of PVC and delays the deepening of the color of PVC.

The effect of the linking position of the oligo(ethylene oxide) segment on the electrochemical properties of naphthalimide-based polymer cathode materials was investigated. For comprehensive analysis, the influence of the alkyl segment in the main chain on the performance of the polymer was also compared. Polymers with alkyl backbone, oligo(ethylene oxide) backbone, and oligo(ethylene oxide) side chains are termed PNDIB, PNDIO, and PNIOS, respectively. The mobility of lithium ion in polymer PNDIB, PNDIO, and PNIOS electrodes was assessed via the galvanostatic intermittent titration technique (GITT). Relative to the alkyl backbone polymer PNDIB, PNIOS, and PNDIO with oligo(ethylene oxide) chains have a higher mobility of lithium ions because the ether groups are favorable for lithium ion transport. Meanwhile, polymer PNIOS has better electronic conductivity due to the advantage of a conjugated backbone for electron transport. Therefore, PNIOS has the best conductivity of the three polymers, resulting in the highest discharge specific capacity and superior cyclic and rate performance. Specifically, PNIOS delivers an initial discharge specific capacity of 162.9 mAh g-1 at 0.1C, retaining 91.4% of its capacity after 120 cycles. At a high rate of 5C, it maintains a discharge capacity of 130.5 mAh g-1 after 5000 cycles. These findings position PNIOS as a promising candidate for lithium-ion battery cathodes.

Developing polymer-based organic afterglow materials with switchable ultralong organic phosphorescence (UOP) that are insensitive to moisture remains challenging. Herein, two organic luminogens, BBCC and BBCS, were synthesized by attaching 7H-benzo[c]carbazole (BBC) to benzophenone and diphenyl sulfone. These two emitters were employed as guest molecules and doped into epoxy polymers (EPs), which were constructed by in situ polymerization to achieve polymer materials BBCC-EP and BBCS-EP. It was found that BBCC-EP and BBCS-EP films exhibited significant photoactivated UOP properties. After light irradiation, they could produce a conspicuous organic afterglow with phosphorescence quantum yields and lifetimes up to 5.35% and 1.91 s, respectively. Meanwhile, BBCS-EP also presented photochromic characteristics. Upon thermal annealing, the UOP could be turned off, and the polymer films recovered to their pristine state, showing switchable organic afterglow. In addition, BBCC-EP and BBCS-EP displayed excellent water resistance and still produced obvious UOP after soaking in water for 4 weeks. Inspired by the unique photoactivated UOP and photochromic properties, BBCC and BBCS in the mixtures of diglycidyl ether of bisphenol A (DGEBA) and 1,3-propanediamine were employed as security inks for light-controlled multilevel anticounterfeiting. This work may provide helpful guidance for developing photostimuli-responsive polymer-based organic afterglow materials, especially those with stable UOP under ambient conditions.

The effect of different carboxylic acid substituents on the electrochemical performance of polythiophene anode materials was discussed. In terms of cycle and rate performance, isophthalic acid substituted polythiophene (P3TBDCOOH) outperforms formic and parabenzoic acid substituted polythiophenes (P3-TCOOH and P3-TBCOOH). P3-TBDCOOH has a specific capacity of 681.1 mAh g(-1) after 100 cycles at 50 mA g(-1) and a capacity of 340.8 mAh g(-1) after 1000 cycles at 1000 mA g(-1). According to density functional theory calculations, P3-TBDCOOH and P3-TBCOOH with a benzene ring between the thiophene ring and the carboxyl group have higher conductivity than P3-TCOOH without a benzene ring, and P3-TBDCOOH shows stronger conductivity than P3TBCOOH and P3-TCOOH. The results imply that the pendant isophthalic acid can enhance the electrochemical activity of polythiophene, increasing the reversible capacity.

Two polymer systems containing 9 H -dibenzo[ a , c ]carbazole derivatives showed phosphorescence quantum yields and lifetimes of up to 13.5% and 3.01 s after photoactivation.

Peryleneimide and its derivatives have excellent thermal and chemical stability and have been extensively studied as cathode materials for lithium-ion batteries. In this paper, an isophthalic acid-functionalized peryleneimide (PI-COOH) anode active material is provided, the capacity storage mechanisms of PI-COOH electrodes are explored, and the cycling performance and rate capability of PI-COOH/Li batteries are investigated. In the total capacity storage of the PI-COOH electrode, the diffusion process provides about 69%. The PI-COOH electrode exhibits good cycling stability and rate capability, with a specific capacity of 580 mAh g-1 after 100 cycles at a current density of 50 mA g-1 and a specific capacity of 286.6 mAh g-1 after 1000 cycles at a current density of 1000 mA g-1. The results suggest that PI-COOH is a potential anode material for Li-ion batteries.

The artificial aging behavior of pure HIPS and stabilized HIPS was studied under the accelerated conditions of UVA, UVB and xenon lamps. The results showed that the carbonyl and hydroxyl absorption peaks of HIPS increased with the aging time. After UVB aging, the elongation at break and impact strength of pure HIPS decreased significantly, the tensile strength and bending strength decreased gradually,and the bending modulus increased, while the corresponding mechanical properties of stabilized HIPS decreased slowly. SEM showed that a lot of cracks were found on the surface of pure HIPS after UVB aging,and the stabilized HIPS showed good aging resistance.

Converting small organic molecules to their lithium salts or polymerization effectively solves the capacity fading caused by the dissolution of small organic molecules in electrolytes. While polymer lithium salts have the characteristics of small molecular lithium salts and polymers and can obtain good cycle stability and rate performance. The 3-carboxylithium substituted thiophene (3-TCOOLi) and polymer (P3-TCOOLi) anode materials for lithium-ion batteries were synthesized, and their electrochemical properties were compared. Compared with the small-molecule lithium salt 3-TCOOLi electrode, the polymer P3-TCOOLi electrode exhibits superior cycling and rate performance. The P3-TCOOLi electrode still has a specific capacity of 390 mAhg(-1) after 100 cycles at a current density of 50 mAg(-1). During the rate charge and discharge process, when the current density increased to 1000 mAg(-1), the specific capacity was 305 mAh g(-1). It shows that the idea of small molecule lithium salt polymerization is feasible.

Two poly(arylamine-imide)s, poly(N,N,N′,N′-tetraphenyl-1,4-benzenediamine naphthalenediimide) (PDDP-NI) and poly(N,N,N′,N′-tetraphenyl-1,4-benzenediamine perylenediimide) (PDDP-PI), were successfully prepared by condensation polymerization of an amine monomer N,N,N′,N′-tetraphenyl-1,4-benzenediamine (DDP) with dianhydride monomer 1,4,5,8-naphthalenetetracarboxylic dianhydride (NTCDA) or 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA). The DDP units in the polymer can reversibly dope/dedope the PF 6 − anion, while the naphthalenediimide (NI) unit or perylene diimide (PI) unit can reversibly insert/extract the lithium cation. The lithium ion half-cells based on the polymer cathode and the lithium anode are assembled and the electrochemical properties are tested. Due to the high voltage of the DDP unit in the polymer backbone, lithium-ion half-cells based on PDDP-NI and PDDP-PI cathodes provide a high average discharge voltage of about 3.2 V. Moreover, the as-prepared polymer materials exhibit long-cycle performance, PDDP-NI remains 89% capacity after 500 cycles at 10 C and PDDP-PI maintains 98% capacity after 1000 cycles at 10 C, furthermore, their coulombic efficiency close to 100% at all current rates tested, which shows that these organic cathode materials have potential applications in long-cycle lithium-ion batteries.

A 3-anthraquinone substituted polythiophene (poly[3-(2-anthraquinone)-2,5-thiophene], P3-AQT)) was synthesized by chemical oxidation polymerization using FeCl3 as oxidant. The structure and thermal stability of P3-AQT were characterized by infrared spectroscopy and thermogravimetric analysis. Due to its electrochemical activity in the range of 0-3.0 V, P3-AQT can be used as an anode material for lithium-ion batteries. The P3AQT/Li batteries were assembled and their electrochemical properties were studied. P3-AQT electrodes can deliver an initial charge capacity of 791 mAh g-1 at a current density of 50 mA g-1 and show good cycle stability at high current density. When the current density is 1000 mA g-1, the initial charge specific capacity is 710 mAh g-1, and the specific capacity remains at 505 mAh g-1 after 100 cycles. The results indicate that the introduction of anthraquinone at the 3-position of polythiophene can increase the reversible capacity of polythiophene and P3-AQT is a potential anode material for lithium-ion batteries.

Ammonium polyphosphate (APP) and soy protein (SP) were used to form biodegradable intumescent flame retardants (BIFR) and further combined with halloysite nanotubes (HNTs) to prepare environmentally friendly intumescent flame retardants (EIFR) to enhance the flame retardancy of poly(butylene succinate) (PBS). Thermogravimetric analysis (TGA), cone calorimeter test and the observation of char residue showed that SP acted as both char source and gas source in BIFR. BIFR with APP/SP (2/1) had the best char-forming capability for PBS, significantly increasing the limiting oxygen index (LOI), reducing peak heat release rate (PHRR) and total heat release (THR), but increasing the total smoke release (TSR). HNTs had a synergistic effect with BIFR to improve the flame retardancy of PBS when at an appropriate content. Addition of 1.0 wt% HNTs increased the LOI, and reduced the PHRR and THR, especially the TSR. However, the synergistic effect became week or diminished when the content of HNTs increased to 1.5 wt% and 3.0 wt%. The possible flame retardant mechanism of EIFR for PBS was proposed. Mechanical test showed that HNTs improved the tensile strength and impact strength of PBS/EIFR composites. The result of soil burial test indicated that BIFR accelerated the biodegradation of PBS. This work may offer a strategy for providing environmentally friendly flame retardants for biodegradable polymers such as PBS, and also addressing the environmental harmfulness of traditional intumescent flame retardants.