Ion Diffusion Research Articles

Preparation of Ordered Nanohole Arrays by Two-Step Anodization of Austenitic Stainless Steel Substrates.

An anodic oxide film with a regular pore arrangement was formed by the two-step anodization of an austenitic stainless steel (JIS SUS304) substrate. In this study, we determined the anodization conditions under which the pore arrangement in the anodic oxide film became self-organized. After removing the anodic oxide film formed by the first anodization with a mixture containing CrO3 and HF, the residual substrate was anodized under the same conditions as those in the first anodization. As a result, we found that it was possible to form an anodic oxide film with pores arranged in a regular pattern from the surface to the bottom. This is the first report on the formation of anodic oxide films with ordered nanohole array structures by the two-step anodization of austenitic stainless steel. The interpore distance of the resulting nanohole array structures can be controlled by changing the anodization conditions. By measuring the capacitance of the anodic oxide film, we confirmed that its properties depended on the heat-treatment temperature and pore depth. In addition, no significant decrease in the capacity of anodic oxide films with ordered nanohole array structures was observed, even when the scan rate of the cyclic voltammogram measurement was increased. This is considered to be because the cylindrical pores facilitate ion diffusion to the bottom of the holes. Anodic oxide films obtained by the anodization of austenitic stainless steel substrates can be applied as electrodes for capacitors.

Temperature Dependent Growth Kinetics of Pd Nanocrystals: Insights from Liquid Cell Transmission Electron Microscopy.

Quantifying the role of experimental parameters on the growth of metal nanocrystals is crucial when designing synthesis protocols that yield specific structures. Here, the effect of temperature on the growth kinetics of radiolytically-formed branched palladium (Pd) nanocrystals is investigated by tracking their evolution using liquid cell transmission electron microscopy (TEM) and applying a temperature-dependent radiolysis model. At early times, kinetics consistent with growth limited is measured by the surface reaction rate, and it is found that the growth rate increases with temperature. After a transition time, kinetics consistent with growth limited by Pd atom supply is measured, which depends on the diffusion rate of Pd ions and atoms and the formation rate of Pd atoms by reduction of Pd ions by hydrated electrons. Growth in this regime is not strongly temperature-dependent, which is attributed to a balance between changes in the reducing agent concentration and the Pd ion diffusion rate. The observations suggest that branched rough surfaces, generally attributed to diffusion-limited growth, can form under surface reaction-limited kinetics. It is further shown that the combination of liquid cell TEM and radiolysis calculations can help identify the processes that determine crystal growth, with prospects for strategies for control during the synthesis of complex nanocrystals.

Lithium Phosphorous Oxynitride as an Advanced Solid‐State Electrolyte to Boost High‐Energy Lithium Metal Battery

AbstractLithium phosphorous oxynitride (LiPON) as one of the most successful solid‐state electrolytes (SSEs), has attracted great interest both in academia and technology due to its exceptional interfacial compatibility, broad electrochemical stability window, and excellent thermal stability, which enables the realization of extremely stable electrolyte/electrode interphase toward high‐energy density solid‐state lithium‐metal batteries (SSLMBs). However, insufficiency in ionic diffusion, mechanical robustness, and interfacial stability hinder its commercialization process. Herein, the characteristics of amorphous structure LiPON, fundamental understanding on the bulk ionic diffusion and electrode/electrolyte interface are systematically discussed, and the improvement strategies to boost the electrochemical performance are highlighted. Then, innovative characterization and computational methods help to unravel the design principle of LiPON are summarized. Furthermore, the approaches to realize high‐efficient preparation of LiPON are analyzed, followed by the investigation of present application of LiPON in current batteries. Finally, remaining challenges associated with the fundamental understanding and rational prediction of structure and interface design, high efficient preparation, and potential opportunities for future application of LiPON are properly prospected.

Structure and Physicochemical Properties of Solutions of Lithium Polysulfides in Tetrasolvate of Lithium Perchlorate with Sulfolane Molecular Dynamics Modeling.

Lithium polysulfides are intermediate products formed during the discharge and charge of lithium-sulfur batteries and have good solubility in electrolyte solutions. Therefore, the properties and structure of solutions of lithium polysulfides in electrolyte solutions affect the energy characteristics of the lithium-sulfur battery. In this work, the structure and physicochemical properties (density, ionic conductivity, and self-diffusion coefficients) of solutions of lithium disulfide, tetrasulfide, and octasulfide in lithium perchlorate tetrasolvate with sulfolane in a wide range of concentrations (0.2-12 M) were studied using the molecular dynamics method. With increasing concentrations of lithium polysulfides, the proportion of sulfur atoms in the coordination sphere of the lithium cation increases and the proportion of sulfolane molecules decreases. It has been established that the ability of the polysulfide anion to act as a bridging ligand leads to the formation of clusters, including lithium perchlorate, lithium polysulfides, and sulfolane. It has been shown that the tendency to form clusters increases with an increasing number of sulfur atoms in the polysulfide anion. At high concentrations of lithium polysulfides, regardless of their size, the electrolyte system becomes a single cluster. With an increase in the concentration of lithium polysulfides in the electrolyte system, its density increases and the ionic conductivity and diffusion coefficients of the system components decrease.

Electrochemical Na+/K+ Ion Exchange in Zeolitic Vanadium(IV) Borophosphate K1.33Na0.67[VO(B2O)(PO4)2(HPO4)]·1.63H2O as Cathode Material for Sodium-Ion Batteries.

Electrochemical ion exchange has recently been demonstrated to be a unique method for the preparation of novel cathode materials, which cannot be accessible by traditional direct synthesis routes. In this study, the vanadium borophosphate compound K1.33Na0.67[VO(B2O)(PO4)2(HPO4)]·1.63H2O (KNVBP) with zeolitic framework exhibits fast electrochemical Na+/K+ ion exchange when used as cathode material in sodium-ion batteries (SIBs). Ex situ structural analyses and electrochemical measurements confirm that most of the K+ ions in the parent KNVBP can be extracted and exchanged by Na+ ions after the first charge/discharge cycle. The in situ-generated Na-rich phase shows reversible electrochemical activity at approximately 3.9 V versus Na+/Na with a specific capacity of 52.9 mAh g-1, comparable to 96.2% of the theoretical capacity. Moreover, enhanced ionic diffusion kinetics can be achieved after the Na+/K+ exchange. This study provides a valuable insight into the electrochemical ion exchange in polyanion compounds toward application in metal-ion batteries.

Designing Dense, Robust, and Ion-Diffusion-Effective Electrodes from Natural Wood Material toward High-Volumetric-Performance Supercapacitors.

Assembling active materials into dense electrodes is a promising way to obtain high-volumetric-capacitance supercapacitors, but insufficient ion channels in the dense structure lead to a low rate capability. Herein, a dense and robust wood electrode with a large MXene volumetric mass loading (1.25 g cm-3) and abundant ion diffusion channels is designed via a facile capillary-force-driven self-densification strategy. Specifically, MXene is assembled onto a wood cell wall, endowing the wood electrode with good electrical conductivity (86 S cm-1) and high electrochemical activity (5.9 F cm-2 at 1 mA cm-2). Notably, the oriented channels along with spaces between adjacent microfibrils recast after densification ensure efficient ion transport for the wood electrode, achieving an excellent rate capability with a high capacitance retention of 77% from 1 to 20 mA cm-2. Meanwhile, the capillary force induces self-densification on the softened wood cell wall, resulting in a highly compact and robust structure for the wood electrode.

Aqueous Multivalent Metal-ion Batteries: Toward 3D-printed Architectures.

Energy storage has become increasingly crucial, necessitating alternatives to lithium-ion batteries due to critical supply constraints. Aqueous multivalent metal-ion batteries (AMVIBs) offer significant potential for large-scale energy storage, leveraging the high abundance and environmentally benign nature of elements like zinc, magnesium, calcium, and aluminum in the Earth's crust. However, the slow ion diffusion kinetics and stability issues of cathode materials pose significant technical challenges, raising concerns about the future viability of AMVIB technologies. Recent research has focused on nanoengineering cathodes to address these issues, but practical implementation is limited by low mass-loading. Therefore, developing effective engineering strategies for cathode materials is essential. This review introduces the 3D printing-enabled structural design of cathodes as a transformative strategy for advancing AMVIBs. It begins by summarizing recent developments and common challenges in cathode materials for AMVIBs and then illustrates various 3D-printed cathode structural designs aimed at overcoming the limitations of conventional cathode materials, highlighting pioneering work in this field. Finally, the review discusses the necessary technological advancements in 3D printing processes to further develop advanced 3D-printed AMVIBs. The reader will receive new fresh perspective on multivalent metal-ion batteries and the potential of additive technologies in this field.

High-Capacity and Ultra-Long-Life Mg-Metal Batteries Enabled by Intercalation-Conversion Hybrid Cathode Materials.

The advancement of rechargeable Mg-metal batteries (RMBs) is severely impeded by the lack of suitable cathode materials. Despite the good cyclic stability of intercalation-type compounds, their specific capacity is relatively low. Conversely, the conversion-type cathodes can deliver a higher capacity but often suffer from poor cycling reversibility and stability. Herein, a WSe2/Se intercalation-conversion hybrid material with elemental Se uniformly distributed into WSe2 nanosheets is fabricated via a simple solvothermal method for high-performance RMBs. The uniformly introduced Se confined in WSe2 nanosheets can not only efficiently improve the conductivity of the hybrid cathodes, facilitating the fast electron transport and ion diffusion, but also provide additional specific capacity. Besides, the WSe2 can effectively inhibit the detrimental Se dissolution and polyselenide shuttle, thereby activating the activity of Se and improving its utilization. Consequently, the synergy of intercalation and conversion mechanisms endows WSe2/Se hybrids with superior reversible capacity of 252mAhg-1at 0.1Ag-1 and ultra-long cyclability of up to 5000 cycles at 2.0Ag-1 with capacity retention of 78.1%. This work demonstrates the feasibility of the strategy by integrating intercalation and conversion mechanisms for developing high-performance cathode materials for RMBs.

Synergizing Electron and Ion Transports of Ti3C2TX MXene Fiber via Dot‐Sheet Heterostructure and Covalent Ti─C─Ti Cross‐Linking for Efficient Charge Storage and Thermal Management

AbstractTi3C2TX MXene with the merits of metallic conductivity, superhigh volumetric capacitance, and efficient absorption of the electromagnetic wave is considered a promising building block for fiber fabrication; nevertheless, the simultaneous improvement in electrochemical charge storage and electrical conductivity/thermal management is seldom achieved for MXene‐based fibers due to the contradictory in material design. Typically, aligned and densified packing of MXene fibers is highly desired for an enhanced intra‐/inter‐flake electron transport; however, the narrowed inter‐layer spacing restricts the kinetics of ion diffusion (the intercalation/de‐intercalation of electrolyte ions) and diminishes the accessible active sites for charge storage. Herein, the electron and ion transports of Ti3C2TX MXene fiber are synergized via a unique dot‐sheet heterostructure covalently bonded by Ti─C─Ti which provides the optimal inter‐layer spacing for rapid ion diffusion and enhances the intra‐/inter‐flake cross‐linking for fast electron transport. As a result, the obtained fiber offers an improved conductivity of 2405 S cm−1, a desirable capacitance of 1597 F cm−3, an impressive energy density of 19.8 mWh cm−3 for the assembled supercapacitor, superior Joule heating performance, and a photo‐thermal temperature. These remarkable attributes enable their practical applications in energy‐supply scenarios, such as powering LEDs and wearable thermal management.

Functional Binder with Enhanced Chemical Adsorption for Black Phosphorus Anode in Lithium‐Ion Capacitors

AbstractBlack phosphorus (BP) has been recognized as an ideal anode material for fast‐charging lithium (Li)‐ion capacitors (LICs) due to its high theoretical capacity (2596 mAh g−1), appropriate lithiation potential (0.7 V vs Li+/Li) and fast ion diffusion capability. However, large volume change and soluble polyphosphides (LixPs)‐based intermediates during charging‐discharging process seriously deteriorate cycling performance. To address the aforementioned issues, an elaborated design is reported on the binder for BP electrode. The ‐NH2 polar functional group in grafted chitosan (GCS) binder presents strong chemical anchoring effect for both BP and soluble LixPs, achieving superior adhesion force and LixPs constraining capability for enhanced structure integrity of BP electrode. In addition, GCS exhibits strong Li‐ion binding energy that promotes the Li‐ion adsorption at electrode level, leading to a boosted cycle life for BP. As a result, the graphene (G) incorporated BP electrode using GCS binder shows specific capacity of 997.6 mAh g−1 after 400 cycles at 1 A g−1. This study unravels the crucial role of functional groups for binder in high‐performance BP electrode.

A Machine Learning‐Enhanced Framework for the Accelerated Development of Spinel Oxide Electrocatalysts

AbstractThe surging demand for sustainable energy has spurred intensive research into electrochemical conversion devices such as fuel cells, water splitting, and metal‐air batteries. The performance of oxygen electrocatalysts significantly impacts overall electrochemical efficiency. Recently, spinel oxides (AB2O4) have emerged as promising candidates; however, the scarcity of prior studies underscores the need for a thorough and comprehensive exploration. This study presents a computational framework that integrates machine learning and density functional theory (DFT) calculations for the systematic screening of 1240 spinel oxides. The data scarcity is addressed while enhancing prediction accuracy. Selected candidates are identified to outperform the benchmarking perovskite oxide. Additionally, their potential as mixed ionic and electronic conductors with a 3D network of ion diffusion pathways is highlighted. To further enhance the understanding and prediction of stability, catalytic activity, and reaction mechanisms, a new undemanding descriptor is introduced: the covalency indicator. This study offers a design principle for the development of high‐performance spinel oxide oxygen electrocatalysts.

Copper(II)-Tannic Acid@Cu with In Situ Grown Gold Nanoparticles as a Bifunctional Matrix for Facile Construction of Label-Free and Ultrasensitive Electrochemical cTnI Immunosensor.

Sensitive detection of cardiac troponin I (cTnI) is of great significance in the diagnosis of a fatal acute myocardial infarction. A redox-active nanocomposite of copper(II)-tannic acid@Cu (CuTA@Cu) was herein prepared on the surface of a glassy carbon electrode by electrochemical deposition of metallic copper combined with a metal stripping strategy. Then, HAuCl4 was in situ reduced to gold nanoparticles (AuNPs) by strong reductive catechol groups in the TA ligand. The AuNPs/CuTA@Cu composite was further utilized as a bifunctional matrix for the immobilization of the cTnI antibody (anti-cTnI), producing an electrochemical immunosensor. Electrochemical tests show that the immunoreaction between anti-cTnI and target cTnI can cause a significant reduction of the electrochemical signal of CuTA@Cu. It can be attributed to the insulating characteristic of the immunocomplex and its barrier effect to the electrolyte ion diffusion. From the signal changes of CuTA@Cu, cTnI can be analyzed in a wide range from 10 fg mL-1 to 10 ng mL-1, with an ultralow detection limit of 0.65 fg mL-1. The spiked recovery assays show that the immunosensor is reliable for cTnI determination in human serum samples, demonstrating its promising application in the early clinical diagnosis of myocardial infarction.

Synergistic engineering of heterojunction and surface coating to boost Zn storage performance of V2O3-based microspheres as an advanced cathode for aqueous zinc-ion batteries

Vanadium-based compounds are highly regarded as potential cathodes for aqueous zinc-ion batteries (AZIBs) owing to the high theoretical capacity, diverse structural frameworks and abundant oxidation states. Nevertheless, the challenges such as slow diffusion kinetics, low electrical conductivity and inadequate structural stability restrict their further development. Herein, yolk shell-like SiO2-coated V2O3/VN heterojunction microspheres (VON@SiO2) are synthesized through a hydrothermal method followed by annealing and subsequent SiO2 coating. As an advanced cathode for AZIBs, the construction of V2O3/VN heterojunction effectively exposes reactive sites, leads to the reduction in interfacial charge transfer resistance, and thus improves the ion diffusion kinetics, while the surface coating of SiO2 is beneficial for enhancing the structural stability of the material and further reduces the capacity fading. Additionally, the micromorphology of porous yolk shell-like microspheres self-assembled by nanoparticles contributes to the complete penetration of electrolyte and greatly exposing reactive sites. Based on synergistic engineering of heterojunction, surface coating and porous shell-like micromorphology, the synthesized VON@SiO2 delivers excellent specific capacities of 483.5 mAh g−1 at 0.5 A g−1 and 294 mAh g−1 at 10 A g−1, and exhibits impressive cycling performance with 94 % of capacity retention after 1000 cycles at 10 A g−1. Further, in-situ XRD and ex-situ XPS reveals the mechanism of zinc ion storage. This work offers a valuable reference into the development of high-performance cathode materials for AZIBs by co-engineering of heterojunction, surface coating and micromorphology optimization.

Chitin-Derived Hierarchical Meso- and Microporous Carbon Enables High-Rate Sulfur Cathode of Sodium-Sulfur Batteries.

Room temperature Na-S batteries are considered as a promising alternative energy storage system because of their abundant material resources and high theoretical energy density. However, the severe polysulfide shuttle effect and slow reaction kinetics hinder their practical application. Herein, a hierarchical meso- and microporous carbon with nitrogen self-doping (NSPC) is prepared using chitin as the carbon precursor and serves as a novel host to confine the sulfur (S⊂NSPC). An optimized structure of NSPC, including abundant graphite nanocrystals, large pore volume of 1.76 cm3 g-1, and large specific surface area of 2073 m2 g-1 is obtained at the carbonization temperature of 1000 °C. These merits contribute to significantly enhanced charge transfer and ion diffusion of the as-prepared S⊂NSPC-1000 cathode, which exhibits the outstanding sodium storage performance, including high reversible capacities of 1207 mAh g-1 at 0.1 C and 891 mAh g-1 at 2 C and stable cycling with a low capacity decay for 400 cycles at 1 C, among other S⊂NSPC cathodes and previously reported cathodes for Na-S batteries. This cathode can also afford stable cycling at a high sulfur loading.

Heterostructure-anchored 3D CNT-bridged graphene architecture via layer-by-layer structural engineering for thick electrodes of supercapacitors

The emerging thick electrode concept is dedicated to maximize active material areal loading at the device-scale through straightforward structural designs to meet the high energy density demand. Nevertheless, overcoming the sluggish charge kinetics and complex manufacturing route in thick composite electrodes is still challenging. Herein, a novel all-laser structural engineering protocol is developed to construct MnO-Mn3O4/MnS heterostructure-anchored 3D porous graphene architecture with reinforced carbon nanotube (CNT) interface (MHGC) by layer-by-layer laser induction of polyethersulfone film containing manganese acetate precursors without introducing any templates or catalysts. Creatively, along with the synchronous generation of porous graphene and multivalent manganese compounds heterostructures, a uniform distribution process of nanoparticles is integrated into a one-step in-situ laser irradiation, which is unique and straightforward for preparing thick composite electrodes. Besides, the interlayer bridging of CNT network between MnO-Mn3O4/MnS/graphene layers accelerates electron transport, accompanied by the ameliorative deep diffusion of ions by open graphene macropores derived from laser-assisted vaporization. Thanks to the configuration of efficient electronic bridge and ion channel, combined with multi-heterointerface and fast surface reaction kinetics endowed by heterostructure nanoparticles, MHGC electrode with a thickness of 442 μm delivers a high specific capacitance of 954.5 mF cm−2 (at 0.5 mA cm−2). The assembled symmetrical supercapacitor with LiCl aqueous electrolyte exhibits a broadened potential window of 1.3 V, obtaining a prominent energy density (39.99 μWh cm−2) and power density (1625 μW cm−2). This advanced laser engineering and enabled thick electrodes open a brand-new avenue in burgeoning energy chemistries, not limited to supercapacitors and rechargeable batteries.

Fast Responsive and High-Strain Electro-Ionic Soft Actuator Based on the 3D-Structure MXene-EGaIn/MXene Bilayer Composite Electrode.

Electro-ionic soft actuators have garnered significant attention owing to their promising applications in flexible electronics, wearable devices, and soft robotics. However, achieving high actuation performance (large bending strain and fast response time) of these soft actuators under low voltage has been challenging due to issues related to ion diffusion and accumulation. In this study, an electro-ionic soft actuator is fabricated using Ti3C2Tx MXene and eutectic gallium-indium (EGaIn) composite material as the bilayer electrode and methylammonium formate/1-ethyl-3-methylimidazolium tetrafluoroborate/poly(vinylidene fluoride) (MAF-EMIMBF4/PVDF) as the ionic liquid-type electrolyte. The research results indicate that the prepared soft actuator exhibits excellent actuation performance with a peak-to-peak displacement of 35 mm and a bending strain of 0.69% (a peak-to-peak strain of 1.38%) under a low voltage (3 V). The electro-ionic soft actuator shows a wide frequency range (0.1-10 Hz), fast response time (0.35 s), and a rise time of 7.5 s. Furthermore, it demonstrates good cyclic durability, with a retention rate of 92.5% of its performance for 10 000 cycles. These excellent performances are attributed to the 3D structure of the Ti3C2Tx-EGaIn/Ti3C2Tx bilayer composite electrode, as well as the characteristics of the low viscosity, high conductivity, small ion volume, and larger volume difference between cations and anions in MAF ionic liquid. The high-performance electro-ionic soft actuator can be used in various fields such as artificial muscles, tactile devices, and soft robots.

Validation of conductivity tensor imaging against diffusion tensor magnetic resonance electrical impedance tomography

Diffusion tensor magnetic resonance electrical impedance tomography (DT-MREIT) and electrodeless conductivity tensor imaging (CTI) are two emerging modalities that can quantify low-frequency tissue anisotropic conductivity properties by assuming similar properties underlie ionic mobility and water diffusion. While both methods have potential applications to estimating neuro-modulation fields or formulating forward models used for electrical source imaging, a direct comparison of the two modalities has not yet been performed in-vitro or in-vivo. Therefore, the aim of this study was to test the equivalence of these two modalities. We scanned a tissue phantom and the head of human subject using DT-MREIT and CTI protocols and reconstructed conductivity tensor and effective low frequency conductivities. We found both gray and white matter conductivities recovered by each technique were equivalent within 0.05 S/m. Both DT-MREIT and CTI require multiple processing steps, and we further assess the effects of each factor on reconstructions and evaluate the extent to which different measurement mechanisms potentially cause discrepancies between the two methods. Finally, we discuss the implications for spectral models of measuring conductivity using these techniques. The study further establishes the credibility of CTI as an electrodeless non-invasive method of measuring low frequency conductivity properties.

K-ion modified V2O5 with abundant oxygen defects as cathode for aqueous zinc-ion battery

Aqueous zinc-ion batteries (ZIBs) are anticipated to be used for grid-scale energy storage because of their low cost, abundant resources, high safety, and non-toxicity. In this study, K-ion modified V2O5 with abundant oxygen defects (K0.1V2O5) was prepared using a one-step hydrothermal reaction followed by heat treatment. K0.1V2O5 showed remarkable specific capacity (307.9 mAhg−1 at 0.2 Ag−1), exceptional rate capability (184.3 mAhg−1 at 10 Ag−1), and good cycling stability (88.5 % capacity retention rate after 2000 cycles at 10 Ag−1). Furthermore, electrochemical kinetics revealed that the electrochemical process of the K0.1V2O5 electrode is governed by both ion diffusion and capacitive contribution, with the diffusion coefficient of Zn2+ ranging between 10−11 and 10−9 cm2 s−1. The exceptional performance of K0.1V2O5 makes it a promising candidate for cathode materials in zinc-ion batteries (ZIBs).

Carbon coated Li3V2(PO4)3 derived from phytic acid with ultra-high rate performance for rechargeable Li ion batteries

The carbon coating strategy has great potential in improving the conductivity of Li3V2(PO4)3 (LVP). However, the preparation of carbon-coated LVP requires an additional carbon source and a complex synthesis process, such as the prereduction of V5+, which poses obstacles to large-scale production. In this article, the phytic acid, a kind of natural biological material with environmental benign and natural abundance, is directly chelated with V3+ and employed as both the phosphorus source and carbon source in the manufacturing procedure of LVP/C material for electrodes. The physical and electrochemical properties of LVP/C material may be tailored by carefully controlling the heat treatment temperature. This process leads to a remarkable boost in key performance metrics, including initial discharge capacity at 1 C (128.35 mAh·g-1), long cycle life at 10 C (115.75 mAh·g-1 after 1000 cycles), and rate capability at 50 C (101.83 mAh·g-1), all attributed to improved electronic conductivity and enhanced ion diffusion kinetics. The simple, novel, and energy-saving method demonstrates great potential for large-scale preparation for the high-performance cathode materials.

Theoretical study of Jahn Teller effect on ion diffusion in trigonal prismatic 1H-MnO2

The trigonal prismatic MnO6 is a basic structural unit of Mn-based compound which has been seldom explored in theoretical and experimental studies. In this paper, the diffusion potential energy surfaces of Li+, Na+, K+, Mg2+, Al3+, and NH4+ ion in trigonal prismatic 1H-MnO2 are presented, which give an intuitionistic picture of the Jahn-Teller effect on the diffusion process. Based on the nudged elastic band method, it is found that the diffusion of ions in trigonal prismatic MnO2 is accompanied by consecutive structural distortion. The low diffusion barriers indicate trigonal prismatic MnO2 is a fast ion conductor. Band structure calculations show the semimetal characteristic of the intercalated compound, which is fit for high electrochemical performance. The details of the diffusion process are also highlighted. Our theoretical study provides an in-depth understanding and research on the fundamentals of the diffusion process in the special configuration in MnO2 and helps to develop novel high-performance electrodes.