Irreversible Trapping Research Articles

Effect of tempering temperature on mechanical properties and hydrogen embrittlement resistance of a dual-precipitation-hardened martensitic steel

ABSTRACT The effects of dual-precipitation on the mechanical properties and hydrogen embrittlement (HE) resistance of a Ti-Mo-alloyed martensitic steel were investigated using a quenching and tempering (QT) procedure. The precipitate-free QT200 sample exhibited high tensile strength and brittle fracture after hydrogen charging. In contrast, the QT300 sample demonstrated a dual-precipitation constitution of (Ti, Mo)C and ϵ-carbide, achieving a high yield strength (∼1400 MPa) without sacrificing tensile ductility (∼10%). More importantly, it showed higher resistance to HE (elongation loss: ∼4.2%) compared to the low-strength QT400 sample. The unusual HE susceptibility of the QT300 samples can be attributed to a higher hydrogen trapping ability of ϵ-carbide compared to (Ti, Mo)C precipitates. This results in high densities of irreversible hydrogen trapping sites and a completely ductile fracture mode characterised by numerous dimples.

Modeling hydrogen diffusion in precipitation hardened nickel-based alloy 718 by microstructural modeling

Abstract Environmentally assisted cracking can significantly affect the performance of high strength alloys and limit material selection to minimize the risk of subcritical crack growth in service. UNS N07718 is widely used in marine service applications and under a variety of conditions, such as: alternate immersion, different levels of cathodic protection, and freely corroding galvanic couples, because of its demonstrated corrosion and fracture resistance in these environments. In this work we developed a representative model of the material microstructure including the metal grains, the material texture, and the precipitates along the grain boundaries and within the grains. The microstructural model was subjected to the boundary conditions identified at the notch root of a fracture mechanics sample and the results are used as input for a simulation of hydrogen diffusion from the surface of the notch, assuming the material has been introduced to a hydrogen producing environment. The diffusion of hydrogen was modeled by Fick’s law and included both hydrostatic stress and mobile dislocation velocity as driving forces. The influence of immobile dislocations was also modeled to account for the irreversible trapping. The results show that hydrostatic stress and immobile dislocation trapping can significantly alter the highest concentration of hydrogen and its location within the microstructure towards the fracture process zone. Mobile dislocation velocity has a small influence in determining the hydrogen distribution near the fracture process zone.

Unraveling Na‐Ion Insertion Mechanisms in Polymer‐Derived SiCN(O) Ceramic via Operando Raman Spectroscopy

AbstractIn this study we investigate the Na insertion process occurring in the “free carbon” phase embedded in two different SiCN(O) matrices with operando Raman spectroscopy. The two SiCN(O) samples have been prepared using two different thermal treatments carried out at 1000 °C (SiCN(O)1000) and 1400 °C (SiCN(O)1400). X‐ray diffraction as well as argon adsorption reveal significant structural and morphological differences between the materials. SiCN(O)1000 shows an amorphous nature whereas SiCN(O)1400 reveals the presence of crystalline β‐SiC, accompanied by a notable increase in surface area (from 56.7 m2/g to 331 m2/g) and micropore volume (from 0.02 cm3/g to 0.12 cm3/g). These alterations in the ceramic matrix due to thermal treatment affect significantly the electrochemical performance with initial de‐sodiation capacities of 112.4 mAh/g and 52.3 mAh/g for SiCN(O)1000 and SiCN(O)1400, respectively. Operando Raman spectroscopy, carried out during the sodiation and de‐sodiation of the SiCN(O) ceramics, reveals the microstructural changes occurring to the “free carbon” phase during the storage of sodium ions. As sodium is inserted, a shift in the G‐band position is observed in both the samples from about 1600 cm−1 to 1555 cm−1, with a concomitant decrease of the D‐band intensity and the distance between defects (LD) growing from 7.5 nm to 17.5 nm. Upon de‐sodiation, SiCN(O)1400 exhibits an inferior storage reversibility compared to SiCN(O)1000. This may be attributed to the irreversible sodium trapping occurring in SiCN(O)1400, highlighted by the reduced efficiency of the electrochemical process.

Interfacial Chemistry Effects in the Electrochemical Performance of Silicon Electrodes under Lithium-Ion Battery Conditions.

Understanding the solid electrolyte interphase (SEI) formation and (de)lithiation phenomena at silicon (Si) electrodes is key to improving the performance and lifetime of Si-based lithium-ion batteries. However, these processes remain somewhat elusive, and, in particular, the role of Si surface termination merits further consideration. Here, scanning electrochemical cell microscopy (SECCM) is used in a glovebox, followed by secondary ion mass spectrometry (SIMS) at identical locations to study the local electrochemical behavior and associated SEI formation, comparing Si (100) with a native oxide layer (SiOx /Si) and etched with hydrofluoric acid (HF-Si). HF-Si shows greater spatial electrochemical heterogeneity and inferior lithiation reversibility than SiOx /Si. This is attributed to a weakly passivating SEI and irreversible lithium trapping at the Si surface. Combinatorial screening of charge/discharge cycling by SECCM with co-located SIMS reveals SEI chemistry as a function of depth. While the SEI thickness is relatively independent of the cycle number, the chemistry - particularly in the intermediate layers - depends on the number of cycles, revealing the SEI to be dynamic during cycling. This work serves as a foundation for the use of correlative SECCM/SIMS as a powerful approach to gain fundamental insights on complex battery processes at the nano- and microscales.

Effects of the cementite morphology on the hydrogen trapping behavior in the pipeline steel

PurposeThe purpose of this study is to investigate the effects of the cementite morphology on the hydrogen trapping behavior in low-alloy pipeline steel.Design/methodology/approachIn this study, the hydrogen trapping behavior in low-alloy pipeline steel was quantitatively studied by a combination of microstructural observations, electrochemical hydrogen permeation experiments and thermal desorption spectroscopy (TDS) analyses.FindingsP-1 and P-2 steels are two samples with different microstructures. The morphology of cementite precipitates in the P-1 and P-2 steels was different. Lamellar cementite is present in P-2 steel and only granular cementite in P-1 steel, which led to a better irreversible hydrogen trapping ability of P-2 steel, which was confirmed by subsequent hydrogen permeation and TDS experiments.Originality/valueThe study of these deep hydrogen trap sites is helpful in improving the hydrogen embrittlement resistance of low-alloy pipeline steels.

Enhancing the hydrogen embrittlement resistance with cementite/VC multiple precipitates in high-strength steel

The superior hydrogen embrittlement (HE) resistance and satisfied work hardening capacity are achieved in high-strength spring steel after hydrogen pre-charging with dispersed multiple precipitates via the multi-microalloying of 1.04 wt% Cr and 0.14 wt% V. The precipitates are determined to be the triplex microstructures, i.e., the isolated (Mn, Cr, V)-enriched cementite, isolated V-enriched VC, and the co-precipitation of cementite and VC. These multiple precipitates could act as the effective hydrogen traps to achieve more potent irreversible hydrogen trapping capacity, thus inhibiting the HE susceptibility by ∼23%. Hence, the strategy of cementite/VC multiple precipitates is beneficial in designing the high-strength and HE-resistant automotive steels.

Hydrogen Diffusion and Trapping in Low-Alloy Tempered Martensitic Steels

Structural characterization of ten low-alloy tempered martensitic steels of varied composition (C, Cr, Mo, Mn, and V contents) and tempering temperature was performed to question the impact of microstructural features on hydrogen state. Thermal desorption spectroscopy and electrochemical permeation data for each alloy were acquired and interpreted in view of hydrogen diffusion/trapping models. This large database provided precise information regarding solubility, diffusion coefficient, activation energies for diffusion and trapping, hydrogen distribution into lattice, and reversible and irreversible trap sites. The results reveal a tendency for the apparent diffusion coefficient to decrease with increasing yield strength, mainly related to the density of trap sites rather than lattice diffusion. Estimates of trapping at dislocation core could explain the irreversible trapping in the six steels with sub-surface hydrogen concentration smaller than 1.5 wppm. For the four steels with higher solubility, it was calculated the superabundant vacancies concentration necessary to justify the amount of trapping sites. The steel with the highest Mo and V contents presented superior solubility of trapped hydrogen which was related to its precipitation of few nanometers in size. It was considered irreversible trapping at carbon vacancies as well as reversible trapping at elastic strain fields around the detected MC carbides.

Understanding the migration mechanism of hydrogen atom from the α-Fe matrix into nano-precipitates via DFT calculations.

The service of high-strength steel suffers from the threat of hydrogen embrittlement and introducing nano-precipitates is an effective avenue to mitigate it. How hydrogen atoms migrate into nano-precipitates is an important question that needs to be clarified. In this study, NEB-based DFT calculations have clearly constructed the energy evolution profiles of the whole process for hydrogen atoms diffusing from α-Fe through the α-Fe/MC (M = V, Ti, Nb) coherent interfaces and finally into the nano-precipitates. The calculation results indicate that a hydrogen atom migrates with difficulty through the α-Fe/MC coherent interfaces and the diffusions in nano-precipitates follow two-step pathways. The C atom vacancy is easier to form in MC nano-precipitates. When introducing a C atom or metallic atom vacancy into the α-Fe/MC interface, the C atom vacancy is the hydrogen trapping site, while the metallic atom vacancy reduces the migration barrier. In addition, once a C atom or metallic atom vacancy is formed in the nano-precipitate, the vacancy will behave as an irreversible trapping site. Finally, electronic structure analyses and distortion energy calculations clearly reveal the effects of the local atomic environment on hydrogen diffusion from α-Fe into nano-precipitates.

Contributions of polarized dislocation walls, internal stresses and vacancies on hydrogen trapping processes in tensile strengthening (100) nickel single crystal

Multiscale impact of dislocation patterns on hydrogen diffusion and trapping mechanisms has been investigated in multi-slip tensile strengthening nickel single crystal. A thorough analysis of dislocation densities and distribution, resulting long-range internal stresses and vacancies concentration was performed at different levels of plastic deformation to precisely characterize the different trapping sites and their impact on apparent diffusion coefficient. Both factors, which govern the hydrogen distributions, have been exanimated using an original analyze combining electrochemical permeation and thermal desorption mass spectroscopy. The results revealed a slowing of the hydrogen diffusion resulting from the phenomenon of trapping by dislocations at different scales. An energetic approach made it possible to associate the reversible trapping with the elastic field of dislocations, and the irreversible trapping with the core of dislocations and vacancies. Moreover, the analyses highlight an implication of the long-range internal stress in the increase of the apparent hydrogen solubility in relation with dislocation cells formation. Finally, a contribution of vacancies to hydrogen trapping is demonstrated with a competition between the formation of vacancies induced by plastic strain and hydrogen ingress.

Dual-carbon coupled three-dimensional superstructures with dominant mesopores targeting fast potassium-ion storage

Carbon materials with three-dimensional (3D) superstructure are a promising anode for potassium-ion batteries (PIBs) because of its rich micropores and defects. However, plenty of micropores often need more time to make electrolyte fully infiltrate, and their irreversible trapping effect will inevitably cause the loss of active K-ions upon cycling. Besides, excessive defects easily arouse poor conductivity because the absence of continuous graphite domains. Hence, dual-carbon coupled 3D superstructure is constructed by pyrolyzing the mixture of zeolitic imidazolate framework and polyvinylpyrrolidone (ZIF8@PVP). Since the preferential decomposition of external PVP, the micropores in ZIF8-derived carbon are effectively inhibited while keeping considerable mesopores, thus substantially shortening ions diffusion distance. Moreover, the decomposition and shrinkage of ZIF8 particles in return prompt the PVP-derived carbon to create more defects, which favors the adsorption storage of K-ions. Not only that, the metallic Zn can catalyze the formation of continuous graphite domains, endowing fast electron migration rate. Accordingly, the optimized product not only delivers an excellent rate (188.2 mAh g−1 at 2 A g−1) and cyclability (over 1800 cycles) in K-half cells, but presents a high energy density (181.5 Wh kg−1) in potassium-ion hybrid capacitors.

Boosting Charge Transfer Via Heterostructure Engineering of Ti2CTx/Na2Ti3O7 Nanobelts Array for Superior Sodium Storage Performance

The poor conductivity, inert charge transmission efficiency, and irreversible Na+ trapping of Na2 Ti3 O7 result in retardant electrons/ions transportation and deficient sodium-ion storage efficiency, leading to sluggish reaction kinetics. To address these issues, an urchin-like Ti2 CTx /Na2 Ti3 O7 (Ti2 C/NTO) heterostructure sphere consisting of Ti2 C/NTO heterostructure nanobelts array is developed via a facile one-step in situ hydrothermal strategy. The Ti2 C/NTO heterostructure can obviously decrease Na+ diffusion barriers and increase electronic conductivity to improve reaction kinetics due to the built-in electric field effect and high-quantity interface region. In addition, the urchin-like vertically aligned nanobelts can reduce the diffusion distance of electrons and ions, provide favored electrolyte infiltration, adapt large volume expansion, and mitigate the aggregation to maintain structural stability during cycles, further enhancing the reaction kinetics. Furthermore, the Ti2 C/NTO heterostructure can effectively suppress many unwanted side reactions between reactive surface sites of NTO and electrolyte as well as irreversible trapping of Na+ . As a result, systematic electrochemical investigations demonstrate that the Ti2 C/NTO heterostructure as an anode material for record sodium-ion storage delivers the highest reversible capacity, the best cycling stability with 0.0065% decay rate for 4500 cycles at 2.0 A g-1 , and excellent rate capability of 172.1 mAh g-1 at 10.0 A g-1 .

Short communication: Mechanism and prevention of irreversible trapping of atmospheric He during mineral crushing

Abstract. A pervasive challenge in noble gas geochemistry is to ensure that analytical techniques do not modify the composition of the noble gases in the samples. Noble gases are present in the atmosphere and are used in a number of manufacturing procedures and by laboratory equipment. Of particular concern is the introduction of atmospheric or laboratory noble gases to samples during preparation before samples are placed in a vacuum chamber for analysis. Recent work has shown the potential for contamination of crushed samples with air-derived He that is not released by placing the samples under vacuum at room temperature. Using pure He gas as a tracer, we show that the act of crushing samples to a fine powder itself can introduce He contamination but that this is easily avoided by crushing under liquid or in an inert atmosphere. Because the He is trapped during crushing, the same concern does not extend to samples that are naturally fine-grained when collected. We also show model results that demonstrate when this effect might significantly impact samples for (U–Th) / He geochronology or 3He cosmogenic nuclide dating. The degree of He contamination from crushing samples to sizes smaller than the > 63 µm range typically used for geochronology is insignificant for samples with a date of at least 1 Ma and 1 ppm U, and the degree of He contamination from crushing samples to sizes smaller than the 100–500 µm range typically used for cosmogenic nuclide dating is also insignificant for samples with a date of at least 10 ka with typical 3He production rates.

The effect of hydrogen on the fracture toughness of friction‐stir welded API 5L X70 pipeline steels

AbstractThe hydrogen embrittlement (HE) leads to severe steel degradation of mechanical properties. The hydrogen atoms diffuse into the steel and get positioned into reversible and irreversible trap sites. The pipe to transport oil and gas needs to be welded to construct long‐distance pipeline projects; thus, friction‐stir welding (FSW) has proven an excellent alternative to joining these pipelines. Therefore, this work assessed and analyzed the influence of hydrogen on the microstructure and fracture toughness of API 5L X70 steel welded by friction‐stir welding. The in‐service conditions were simulated by charging the specimen electrolytically in a 3.5% NaCl water solution with an intensity current of 2 mA·cm−2. According to fracture toughness tests, the base metal (BM) was more affected by hydrogen embrittlement than the friction‐stir zone (SZ), with a fracture toughness reduction of 20% after hydrogen charging. The SZ fracture toughness did not statistically show changes in hydrogen charging by the used times; however, the fracture mechanism changed from ductile to brittle‐like after 4 days of charging. The SZ depicted a better fracture toughness than BM due to the bainitic microstructure, a significant amount of irreversible hydrogen trapping.

Advanced Anode Materials for Sodium-Ion Batteries: Confining Polyoxometalates in Flexible Metal-Organic Frameworks by the "Breathing Effect".

Polyoxometalates (POMs) have shown great potential in sodium-ion batteries (SIBs) due to their reversible multielectron redox property and high ionic conductivity. Currently, POM-based SIBs suffer from the irreversible trapping and sluggish transmission kinetics of Na+. Herein, a series of POMs/metal-organic frameworks (MOFs)/graphene oxide (GO) (MOFs = MIL-101, MIL-53, and MIL-88B; POM = [PMo12O40]3-, denoted as PMo12) composites are developed as SIB anode materials for the first time. Unlike MIL-101 with large pore structures, the pores in flexible MIL-53 and MIL-88B swell spontaneously upon the accommodation of PMo12. Particularly, the PMo12/MIL-88B/GO composites deliver an excellent specific capacity of 214.2 mAh g-1 for 600 cycles at 2.0 A g-1, with a high initial Coulombic efficiency (ICE) of 51.0%. The so-called "breathing effect" of flexible MOFs leads to the relatively tight confinement space for PMo12, which greatly modulates its electronic structure, affects the adsorption energy of Na+, and eventually reduces the trapping of sodium ions. Additionally, the straight and multidimensional channels in MIL-88B significantly accelerate ion diffusion, inducing favored energetic kinetics and thus generating high-rate performance.

Development and Clinical Application of Positron Emission Tomography Imaging Agents for Monoamine Oxidase B.

Monoamine oxidase B (MAO-B) is a high-density protein in the brain mainly found on outer mitochondrial membranes, primarily in astroglia, but additionally in serotonergic neurons and in the substantia nigra in the midbrain. It is an enzyme that participates in the oxidative metabolism of important monoamines including dopamine, norepinephrine, benzylamine, and phenylethylamine. Elevated MAO-B density may be associated with astrogliosis and inhibiting MAO-B may reduce astrogliosis. MAO-B density is elevated in postmortem sampling of pathology for many neuropsychiatric diseases including Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, amyotrophic lateral sclerosis, and alcohol use disorder. Initial development of positron emission tomography (PET) imaging agents focused on analogs of [11C]L-deprenyl, with the most commonly applied being the deuterium substituted [11C]L-deprenyl-D2. This latter radiotracer was modeled with an irreversible trapping compartment reflecting its irreversible binding to MAO-B. Subsequently, [11C]SL25.1188, a reversible binding MAO-B radioligand with outstanding properties including high specific binding and excellent reversibility was developed. [11C]SL25.1188 PET was applied to discover a substantive elevation of MAO-B binding in the prefrontal cortex in major depressive disorder (MDD) with an effect size of more than 1.5. Longer duration of MDD was associated with greater MAO-B binding throughout most gray matter regions in the brain, suggesting progressive astrogliosis. Important applications of [11C]L-deprenyl-D2 PET are detecting a 40% loss in radiotracer accumulation in cigarette smokers, and substantial occupancy of novel therapeutics like EVT301 and sembragiline. Given the number of diseases with elevations of MAO-B density and astrogliosis, and the advance of [11C]SL25.1188, clinical applications of MAO-B imaging are still at an early stage.

Exploiting the capacity merits of Si anodes in the energy-dense prototypes via a homogeneous prelithiation therapy

The practical exploitation of the high-capacity Si anodes suffers from the insufficient cation utilization degree in the energy-dense batteries, which originates from unstable interfacial dynamics, lithiation-induced mechanical stress, and irreversible Li trapping in the alloy intermediates. Herein, we develop a scalable, indirect mechanical calendaring approach to enable the homogeneous prelithiation process, specifically through interpolating an intermediate buffer layer (IBL) with tunable electronic/ionic pathways in-between the lithium foil source and the target high-capacity electrode. Upon the prototype assembly of various prelithiated Si/Graphite anodes (450–1000 mAh g−1 at the constant areal capacity of 4.6 mAh cm−2) and the LiNi0.8Co0.1Mn0.1O2 cathode (NCM811, 23 mg cm−2 for the double-sided electrode), the enhanced Li utilization degree with the highest energy density up to 362 Wh kg−1 could be achieved on the realistic cell level (1.6 Ah pouch model). More encouragingly, the reversible phasic evolution of both the cathode and anode, upon the Li+ inventory replenishment, are real-time tracked by the transmission-mode operando X-ray diffraction (XRD). This IBL-regulated approach is further extended to construct an environmental-adaptive composite film that integrates the metallic Li source, the prelithiation of which could well function even at the extreme humid conditions (long-time shelf life or relative humidity up to 85%).

Synthesis of presodiated B, N Co-doped carbon materials and application in sodium ions batteries with enhanced initial coulombic efficiency

Heteroatoms doped carbon-based materials have attracted abundant attention as an anode material in high-energy density and low-cost sodium ions batteries (SIBs). However, the low initial Coulombic efficiency (ICE) resulted from the irreversible Na trapping and the formation of solid electrolyte interphase (SEI) is denounced in the practical application. In this work, presodiated B and N co-doped carbons are fabricated by a facial one-step synthetic process employing graphitic carbon nitride (g-C3N4) as precursor and NaBH4 as both presodiation agent and B sources. The high doping levels of B and N in the resultant carbon materials lead to a promising Na+ storage capability (308 mAh g−1 at 0.05 A g−1) when served as the anode in SIBs. More importantly, desirable ICE as high as 96.1% was recorded for the obtained presodiated B, N co-doped carbon material benefiting from the pre-incorporated sodium, which passivates the irreversible reactive sites. This work provides a novel route to realize simultaneous presodiation and B, N co-doping within carbon materials, enabling promising Na+ storage capability and enhanced ICE for application in SIBs.

Gap mode induced photo-oxidation of p-methyl thiophenol and relating phenomena

Surface plasmon excitation at a nanogap between adjacent metal nanostructures generates extremely enhanced electric field, which enables us to detect and characterize individual molecules by surface enhanced Raman scattering (SERS). However, versatile nanogap fabrication methods have not been established, making difficult to efficiently exploit a gap mode plasmon in practical applications such as biosensing, biomedical, and environmental analyses. Here, we describe reproducible nanogap assemblies using adjacent metal nanoparticles (MNPs) and MNPs/adsorbates/metal substrates based on the Derjaguin − Landau − Verway − Overbeek theory and irreversible optical trapping of MNPs on metal substrates. The assembled nanogaps between adjacent MNPs, here, M is Ag or Au, enabled us to characterize adsorbates such as solvent shared ion pairs of hydrated metal ions, and three distinct adsorbed states of adenine depending on pH in aqueous solutions. Also we found plasmon-induced oxidation of p-alkyl thiophenol (p-AlkTP) at the nanogap on AgNP/p-AlkTP/Ag films. This oxidation has a specific reactivity at the p-position in the p-AlkTP phenyl ring, while providing intermediate species under nitrogen atmosphere. This specific oxidation is not driven by a thermal process but by a hot carrier transfer process. Thus, the nanogap fabrication methods using adjacent metal nanostructures we developed are promising to elucidate static and dynamical nature of target molecules using SERS spectroscopy.

TiO2 nanoparticle coatings on glass surfaces for the selective trapping of leukemia cells from peripheral blood.

Photodynamic therapy (PDT) using TiO2 nanoparticles has become an important alternative treatment for different types of cancer due to their high photocatalytic activity and high absorption of UV-A light. To potentiate this treatment, we have coated commercial glass plates with TiO2 nanoparticles prepared by the sol-gel method (TiO2 -m), which exhibit a remarkable selectivity for the irreversible trapping of cancer cells. The physicochemical properties of the deposited TiO2 -m nanoparticle coatings have been characterized by a number of complementary surface-analytical techniques and their interaction with leukemia and healthy blood cells were investigated. Scanning electron and atomic force microscopy verify the formation of a compact layer of TiO2 -m nanoparticles. The particles are predominantly in the anatase phase and have hydroxyl-terminated surfaces as revealed by Raman, X-ray photoelectron, and infrared spectroscopy, as well as X-ray diffraction. We find that lymphoblastic leukemia cells adhere to the TiO2 -m coating and undergo amoeboid-like migration, whereas lymphocytic cells show distinctly weaker interactions with the coating. This evidences the potential of this nanomaterial coating to selectively trap cancer cells and renders it a promising candidate for the development of future prototypes of PDT devices for the treatment of leukemia and other types of cancers with non-adherent cells.

Triphenylamine-triazine polymer materials obtained by electrochemical polymerization: Electrochemistry stability, anions trapping behavior and electrochromic-supercapacitor application

Electrochemical energy-saving and storage applications such as electrochromism and supercapacitor were always accompanied by the ions exchange between electrolytes and electrode materials. The repeated ions exchange may cause ions trapping behavior. However, the ions trapping mechanism is still not fully understood, especially for conjugated organic/polymer films. Here we report two triphenylamine-triazine/ditrazine polymers obtained by electrochemical polymerization, namely pTPATz and pTPADTz. During the spectroelectrochemical experimental process, severe loss of charge capacity and optical contrast for both two polymer films were observed after long-term cycling under higher applied potential (1.4 V vs Ag/AgCl) in the electrolyte containing ClO4−. The XPS and FTIR results certificated the ClO4− anions trapping and the formation of weak O···N+ bond similar to hydrogen bond between triphenylamine and ClO4− anions, corresponding to a new binding energy of 402.1 eV of N+ in polymer films after cycling. The repeated ions exchange in the electrochemical charge/discharge process caused the continuous accumulation of O···N+-(C)3 group to form the irreversible anion trapping and charge doping effect, which surely induce the severe electrochemical instability of polymer films pTPATz and pTPADTz. After replacing ClO4−with BF4− anions, the electrochemical or cycling stability can be significantly improved based on two polymer films and their electrochromic-supercapacitor devices. This work provides an in-depth insight into the degradation phenomenon taking place in conjugated organic/polymer films from the viewpoint of ion trapping.