Charge-discharge Process Research Articles

High-Performance Zinc-Ion Hybrid Supercapacitor from Guilin Sanhua Liquor Lees-Derived Carbon Materials.

Aqueous zinc-ion hybrid supercapacitors (ZHSCs) have attracted considerable attention because they are inexpensive and safe. However, the inadequate energy densities, power densities, and cycling performance of current ZHSC energy-storage devices are impediments that need to be overcome to enable the further development and commercialization of this technology. To address these issues, in this study, we prepared carbon-based ZHSCs using a series of porous carbon materials derived from Sanhua liquor lees (SLPCs). Among them, the best performance was observed for SLPC-A13, which exhibited excellent properties and a high-surface-area structure (2667 m2 g-1) with abundant micropores. The Zn//SLPC-A13 device was assembled by using 2 mol L-1 ZnSO4, SLPC-A13, and Zn foil as the electrolyte, cathode, and anode, respectively. The Zn//SLPC-A13 device delivered an ultrahigh energy density of 137 Wh kg-1 at a power density of 462 W kg-1. Remarkably, Zn//SLPC-A13 retained 100% of its specific capacitance after 120,000 cycles of long-term charge/discharge testing, with 62% retained after 250,000 cycles. This outstanding performance is primarily attributed to the SLPC-A13 carbon material, which promotes the rapid adsorption and desorption of ions, and the charge-discharge process, which roughens the Zn anode in a manner that improves reversible Zn-ion plating/stripping efficiency. This study provides ideas for the preparation of ZHSC cathode materials.

First Principles Study of the Structure-Performance Relation of Pristine Wn+1Cn and Oxygen-Functionalized Wn+1CnO2 MXenes as Cathode Catalysts for Li-O2 Batteries.

Li-O2 batteries are considered a highly promising energy storage solution. However, their practical implementation is hindered by the sluggish kinetics of the oxygen reduction (ORR) and oxygen evolution (OER) reactions at cathodes during discharging and charging, respectively. In this work, we investigated the catalytic performance of Wn+1Cn and Wn+1CnO2 MXenes (n = 1, 2, and 3) as cathodes for Li-O2 batteries using first principles calculations. Both Wn+1Cn and Wn+1CnO2 MXenes show high conductivity, and their conductivity is further enhanced with increasing atomic layers, as reflected by the elevated density of states at the Fermi level. The oxygen functionalization can change the electronic properties of WC MXenes from the electrophilic W surface of Wn+1Cn to the nucleophilic O surface of Wn+1CnO2, which is beneficial for the activation of the Li-O bond, and thus promotes the Li+ deintercalation during the charge-discharge process. On both Wn+1Cn and Wn+1CnO2, the rate-determining step (RDS) of ORR is the formation of the (Li2O)2* product, while the RDS of OER is the LiO2* decomposition. The overpotentials of ORR and OER are positively linearly correlated with the adsorption energy of the RDS LixO2* intermediates. By lowering the energy band center, the oxygen functionalization and increasing atomic layers can effectively reduce the adsorption strength of the LixO2* intermediates, thereby reducing the ORR and OER overpotentials. The W4C3O2 MXene shows immense potential as a cathode catalyst for Li-O2 batteries due to its outstanding conductivity and super-low ORR, OER, and total overpotentials (0.25, 0.38, and 0.63 V).

Facile synthesis of cobalt-nickel oxide nanocomposites for trifunctional application towards antioxidant, anticancer and electrochemical performance

Transition metallic mixed oxides have received a lot of curiosity due to their exceptional electrochemical performance and incredibly low cost for hybrid supercapacitors. Herein, we report a facile synthetic approach of cobalt nickel oxide (CNC) composites from Carica papaya leaf extract. The synthesized mixed oxide composite was analyzed by various spectroscopic techniques (IR, UV–Vis, Powder XRD, SEM-EDAX, TEM and XPS). The electrochemical behavior of CNC was investigated by cyclic voltammetry (CV) and galvanostatic charge–discharge (GCD) method in 2 M KOH solution. The composites exhibit specific capacitance of 289.28 F g−1 at 1 A g−1 demonstrating improved charge storage. The electrode retains 81 % of its specific capacitance from the initial value after repeated charge–discharge processes for 2000 cycles. In addition to the electrochemical studies, biological activities such as anti-oxidant and anti-cancer activities of the CNC were examined. The radical scavenging activity of CNC was assessed with different radicals such as DPPH•, ABTS+., NO–, OH•, O2– and the acquired results showed that the composites possessed substantial activity. Anticancer activity of CNC was studied against HepG2 and MM2 cancer cells and the CNC possessed significant activity with the IC50 value of 45.8 and 38.3 µg/ml respectively compared with the standard drug cisplatin. Further apoptogenic nature of the CNC was confirmed with DAPI staining assay.

Stabilizing Layered‐Type K0.4V2O5 Cathode by K Site Substitution with Strontium for K‐Ion Batteries

AbstractDeveloping suitable cathodes with high capacity and high power is challenging for K‐ion batteries. Herein, electrochemical K‐ion storage properties of the layered‐type K0.4V2O5 (KVO) cathode by incorporating divalent strontium ions (Sr2+) into its crystal structure are enhanced. Divalent strontium ions (1.18 Å) are preferentially incorporated into the octahedrally coordinated K (1.38 Å) layers due to the similar ionic size compared to V4+ (0.58 Å). The introduction of 3 mmol of Sr ions in the KVO crystal improves electrical conductivity and reduces K‐ion diffusion energy barriers. In addition, the strong Sr2+ and O2− interaction acts as a structural pillar, suppressing irreversible phase transition during charge–discharge process. Multi‐physics simulations clearly confirm that the K0.34Sr0.03V2O5 (KS3VO) cathode exhibits a more uniform K‐ion distribution and enhanced reactions of K‐ions compared to the KVO cathode at various depths of discharge. As a result, the KS3VO cathode demonstrates improved reversible capacity, cycling stability, and power capability over the KVO cathode in a K‐ion cell. Synchrotron X‐ray analysis reveals how Sr substitution enhances the electrochemical K‐ion storage properties of the KS3VO cathode. In addition, the KS3VO cathode exhibits superior thermal stability and cycling stability in a full cell coupled with a hard carbon anode compared to the KVO cathode.

Exploration of the two-dimensional transition metal phosphide MoP2 as anode for Na/K ion batteries

Transition metal phosphides are regarded to be potential anode materials for alkali metal ion batteries with abundant availability of the constituent elements. However, the volume changes and resulting structure deterioration during the charge-discharge process are challenges. Using evolutionary search combined with ab initio calculations, we discover a dynamically, thermally, and mechanically stable MoP2 monolayer, which turns out to be an excellent anode material for Na-ion batteries providing a high specific capacity of 339 mA h g−1, low diffusion barrier of 0.12 eV, and low open-circuit voltage of 0.48 V. The volume expansion (125%) is found to be decisively smaller than in the case of black phosphorus (443%), for example.

Stabilizing Ni2+ in Hollow Nano MOF/Polymetallic Phosphides Composites for Enhanced Electrochemical Performance in 3D-Printed Micro-Supercapacitors.

Polymetallic phosphides exhibit favorable conductivities. A reasonable design of nano-metal-organic frame (MOF) composite morphologies and in situ introduction of polymetallic phosphides into the framework can effectively improve electrolyte penetration and rapid electron transfer. To address existing challenges, Ni, with a strong coordination ability with N, is introduced to partially replace Co in nano-Co-MOF composite. The hollow nanostructure is stabilized through CoNi bimetallic coordination and low-temperature controllable polymetallic phosphide generation rate. The Ni, Co, and P atoms, generated during reduction, effectively enhance electron transfer rate within the framework. X-ray absorption fine structure (XAFS) characterization results further confirm the existence of Ni-N, Ni-Ni, and Co-Co structures in the nanocomposite. The changes in each component during the charge-discharge process of the electrochemical reactions are investigated using in situ X-ray diffraction (XRD). Theoretical calculations further confirm that P can effectively improve conductivity. VZNPGC//MXene MSCs, constructed with active materials derived from the hollow nano MOF composites synthesized through the Ni2+ stabilization strategy, demonstrate a specific capacitance of 1184 mF cm-2, along with an energy density of 236.75 µWh cm-2 (power density of 0.14 mW cm-2). This approach introduces a new direction for the synthesis of highly conductive nano-MOF composites.

Online cell pressure tracking analysis and sulfur species depositing/stripping behavior study of lithium sulfur batteries

Cell failure is easy occurring in Li-S cell. Electrolyte consumption caused by side-reactions between electrolyte and anode is one of the reasons for the cell failure, but the underlying mechanism for the cell failure is still not clear. To get insight into the electrolyte decomposition, in this work, online cell pressure tracking analysis (OCPTA) is applied to study the gassing effect caused by electrolyte decomposition reactions during charge–discharge processes and the study on depositing/stripping behavior of sulfur species performed. It is found that gassing effect is negligible in the cell with conventional ether-based electrolyte when electrolyte decomposing, but volume effect caused by sulfur species dissolution is notable. Together with the sulfur preferentially depositing on the top surface of cathode, it leads to electrolyte insufficiency on the top surface of electrodes, enhancing the risk of cell failure.

Acidity-Aided Surface Modification Strategy to Enhance In Situ MnO2 Deposition for High Performance Zn-MnO2 Battery Prototypes.

Zn-MnO2 batteries offer cost-effective, eco-friendly, and efficient solutions for large-scale energy storage applications. However, challenges, like irreversible cathode reactions, prolonged cyclability, and electrolyte stability during high-voltage operations limit their broader application. This study provides insight into the charge-discharge process through in situ deposition of active β-MnO2 nanoflakes on a carbon-based current collector. The study elucidates the effect of pH and electrolyte concentration on chemical conversion reactions with Zn, in particular focus on their impact on the two-electron MnO2/Mn2+ reaction crucial for high voltage operation. The electrolyte, characterized by being relatively lean in Mn2+ and with a targeted low pH, enables extended cycling. This research achieves greater cycling durability by integratinga carbon-based cathode current collector with high density of structural defects in combination with cell architectures suitable for large-scale energy storage. A flooded stack-type Zn-MnO2 battery prototype employing the optimized electrolyte demonstrates a high discharge voltage (≈2V) at a substantial discharge current rate of 10mAcm-2. The battery exhibits an impressive areal capacity of ≈2mAhcm-2, maintaining ≈100% capacity retention over 400cycles. This research establishes a promising practical, and cost-effective cathode-free design for Zn-MnO2 batteries, that minimizes additional processing and assembly costs.

The local disorder induced by high-entropy doping results in highly stable cathode materials for aqueous potassium-ion batteries

Aqueous potassium-ion batteries are poised to become leading candidates for next-generation large-scale storage technology due to their low cost and safety features. However, the stability of aqueous potassium-ion battery materials faces significant challenges. The large ionic radius of potassium ions causes significant stress changes in the ordered crystal structure of the materials during the charge-discharge process. To address this issue, we synthesized high-entropy-doped layered manganese oxide (HE-KMO). High-entropy doping reconstructed the electron cloud distribution between the layers of HE-KMO, causing local disorder in HE-KMO. Local disorder reduces the transport barrier by inducing the transport of potassium ions and alleviates the stress on the material. It prevented phase transitions of HE-KMO during charging and discharging, improving the stability of HE-KMO. We used HE-KMO in the cathode material of aqueous potassium-ion batteries. Under a current of 5 A g−1, HE-KMO maintains an outstanding capacity retention after 5000 cycles.

Impact of Li-ions and CO2 on the electrochemical efficiency of Al and Al-4%Sn in KOH electrolyte for alkaline batteries application

This study investigates the electrochemical behavior of aluminum (Al) and aluminum‑tin (Al-Sn) alloy as anodes in aluminum-air (Al-air) batteries in a potassium hydroxide (KOH) electrolyte with varying concentrations of lithium hydroxide (LiOH), in both the presence and absence of carbon dioxide gas (CO2). Experimental techniques such as potentiodynamic polarization (Tafel behavior), galvanostatic charging-discharging processes, and electrochemical impedance spectroscopy (EIS) were employed. Characterization techniques including X-ray diffraction spectroscopy (XRD), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDX) were utilized to analyze the surface products of each electrode. The findings indicate a significant decrease in the corrosion current density (icorr.) for both two electrodes with increasing LiOH concentration, however, Al-Sn exhibits lower values than those of commercial Al. Moreover, the presence of Li-ions revealed an interesting phenomenon of Al, where icorr. gradually decreased with temperature rise. Also, in the presence of CO2, icorr. significantly decreased for both two electrodes, particularly Al-Sn, indicating complete repression of the corrosion process on the surface. The corrosion rate of the studied electrodes in basic solutions, with and without CO2, follows the order: KOH > KOH + LiOH > KOH + LiOH + CO2. Galvanostatic charge-discharge measurements demonstrated higher capacity, improved electrochemical performance, and excellent charge-discharge behavior in the presence of LiOH. The electrochemical findings align well with the results from XRD, SEM, and EDX analysis.

Density functional theory analysis of Na4Mn4Ti5O18 for sodium ion battery electrode

Density functional theory study has been performed on Na4Mn4Ti5O18 to evaluate its application feasibility as an electrode in Na ion battery. Two types of void in the structure of Na4Mn4Ti5O18, viz., Z shaped tunnel and polyhedral pentagonal void, has been observed that act as guest sites for reversible migration of Na+ ions. It is also noted that electrochemically active sites are placed in Z shaped tunnel that act as host for Na+ during anodic response while it acts as the Na+ donor during cathodic response. The Mn atom, located in the Z-shape tunnel, acts as redox active site for both cathodic and anodic response via formation of redox couple Mn+3/Mn+4 and Mn+3/Mn+2 respectively. On the other hand, Mn atom present at square pyramidal site remains inert during charge–discharge process. The redox action in Na4Mn4Ti5O18, occurring due to intercalation and de-intercalation of 2Na+ ions per formula unit, has been noted to exhibit voltage ∼2.63 V and 3.82 V respectively. The theoretical capacity ∼128 mAhg−1 has been estimated corresponding to migration of 2Na+ in Na4Mn4Ti5O18 structure. The present simulation study indicates the possibility of electrode action in Na4Mn4Ti5O18 for sodium ion battery application.

Battery health prediction using two-dimensional multi-channel ensemble models

The accurate assessment of battery health is crucial for maximizing the performance and lifespan of lithium-ion batteries. In this paper, an ensemble model based on a two-dimensional multi-channel convolutional neural network is proposed to predict the maximum usable capacity of lithium-ion batteries. First, based on the charge–discharge process, the characteristic-derived lines of the capacity–voltage (Q–V) curve are extracted. Next, the Gramian angular summation field (GASF) is employed to convert one-dimensional time series data into image matrices, with the aim of preserving temporal characteristics. Finally, the paper discusses the impact of 2D matrix size on prediction results and introduces the use of a 2D multi-channel ensemble model for the unsupervised recognition and extraction of battery decline information from images, marking the first time this approach has been utilized. The experimental results demonstrate that the proposed method effectively captures battery degradation patterns from multiple perspectives. The average mean absolute percentage error of 1.95% and root mean square error of 1.41% on the verified batteries indicate the robustness and generalizability of the approach.

Numerical study of polymer embedded metal hydride-based self-sensing actuator

Metal hydride actuators have amassed increasing attention over the past decade owing to their desirable operational characteristics, such as a high power-to-weight ratio, noiseless and vibration-less operation, lightweight, safety and environmental friendliness. Essentially, there are two ways in which we can attain actuation using hydrides. Primarily, actuation force is generated by the hydrogen gas pressure changes associated with charge–discharge process. Alternatively, the incompressible volumetric changes in the hydride bed during sorption can also result in actuation. However the studies reported on this type of actuators are rare and mostly deal with bimorph actuators. The present study investigates the effect of soft silicone rubber composited metal hydride bed within a hollow stainless steel spring for its potential use as a self-sensing actuator element. LaNi5 is used as the metal hydride alloy. For an equivalent quantity of hydride by mass, the estimated actuation stroke and force for the composite bed actuator are better than their powder bed counterpart (12 mm and 100 N, respectively, in contrast to 5.84 mm and 60 N), due to improved heat transfer. Bed thickness, coil pitch and coil diameter are important geometric parameters which control the performance of the device. As previously reported, hydrogen supply pressure and heat transfer coefficient are found to be important operating parameters controlling the force –stroke characteristics of the actuating element. The simulation study has been executed using COMSOL Multiphysics™ commercial code.

Regulation of morphology and particle size of spinel LiMn2O4 induced by Fe-B co-doping for high-power lithium ion batteries

The spinel LiMn2O4 cathode material shows severe capacity degradation due to Jahn–Teller distortion and dissolution of Mn during the charge-discharge process. Herein, a series of single crystal truncated octahedral of LiFe0.03BxMn1.97−xO4 (0≤x≤0.10) were synthesized by simple solid-state combustion combined with Fe-B co-doping, morphology and particle size controlling strategy. Through Fe-B co-doping, not only the LiFe0.03Mn1.97O4 containing {111}, {100} and {110} planes are successfully controlled to the particles containing only {111} and {100} planes, but also the near-nanometer particles are controlled to bigger submicron sizes. It is found that Fe-B co-doping can enhance the stability of the crystal structure, inhibit Jahn-Teller distortion and reduce the dissolution of Mn. Among them, the optimized LiFe0.03B0.08Mn1.89O4 forms a truncated octahedral single crystal particle with good crystallization and only {111} and {100} crystal faces, and the particle size is around 349.3 nm, showing exceptional high rate capacity and long cycle life. The LiFe0.03B0.08Mn1.89O4 releases a high initial discharge capacity of 107.1 mAh/g with a capacity retention of 77.7% after 1000 cycles at 10 C, which is higher than that of the LiFe0.03Mn1.97O4 (58.8%). Even at 20 C, LiFe0.03B0.08Mn1.89O4 still achieves a high reversible specific capacity (90.4 mAh/g) and outstanding long-cycle stability (81.3%, 1000th). This work provides a scientific basis for the crystal surface control and particle size control of spinel LiMn2O4, which is of great significance for the development of the next generation of high-power lithium-ion batteries.

High performance carboxymethyl cellulose- polyethylene oxide polymer binder for black phosphorus anode in lithium-ion batteries

Black phosphorus (BP) is regarded as a promising anode material due to its high theoretical specific capacity and fast charging safety. However, the problems of huge volume expansion and moderate electrical conductivity may restrict its performance. In this work, we present a novel 3D network binary polymer binder synthesized from carboxymethyl cellulose (CMC) and polyethylene oxide (PEO) for adapt to lithium-ion batteries of BP and graphite (G) composite anode (BP-G). There are the following characteristics of the binder: CMC and PEO are crosslinked through intermolecular forces; while CMC and PEO are connected to BP through strong intermolecular forces, respectively; BP and graphite are connected through PC and POC bonds to form composite anode. So as to form a sturdy structure and effectively accommodate the volume expansion of BP during charging-discharging processes, while avoiding loss of electrical contact between electrode components. Accordingly, the lithium-ion battery shown an excellent electrochemical performance, such as a high initial discharge capacity of 1602 mA h g−1 at 0.5 A/g.

Pomegranate-like α-MoO3-x/C nanospheres as a stable and high-performance Li-ion intercalation host

Orthorhombic MoO3 (α-MoO3) is extensively investigated as a cathode material in Li-ion batteries with high capacity. However, suffering from the irreversible structural transformation and rapid capacity decline during discharge-charge process are still annoyed issues for α-MoO3 based electrodes. Herein, novel pomegranate-like oxygen-deficient α-MoO3/C (α-MoO3-x/C) nanospheres are prepared. The α-MoO3-x/C nanosphere is comprised of ultrafine α-MoO3-x subunits and porous graphitic carbon framework. Interlayer expansions caused by different contents of oxygen vacancies are realized in α-MoO3-x via a controllable oxidation process. When evaluated as the Li-ion intercalation host, the α-MoO3-x/C containing appropriate oxygen vacancies is found to be optimal with remarkable rate capability (230.0 mAh g−1 at 1 C, 54.5 mAh g−1 at 50 C) and long lifetime (69.6% retention after 3000 cycles at 10 C). Electrochemical test shows that the behavior of Li-ion intercalation in the intralayers of α-MoO3-x/C is suppressed effectively and becomes reversible. The structure evolutions during Li-ion intercalation/deintercalation process are investigated by ex situ X-ray diffraction, which reveals that α-MoO3-x/C undergoes lattice breathing rather than structural collapse compared with pure α-MoO3. Moreover, α-MoO3-x/C exhibits enhanced pseudocapacitance and improved Li-ion transport kinetics than pure α-MoO3. These unique features render α-MoO3-x/C an advanced intercalation host for Li-ions.

Influence of phytic acid on corrosion behavior and charge-discharge processes of Pb-2%In alloy anode for lead-acid battery applications

This study investigates the impact of phytic acid on the corrosion behavior and charge-discharge processes of Pb-2 %In alloy, which is commonly used as an anode material in lead-acid batteries. Potentiodynamic polarization, electrochemical impedance spectroscopy measurements, as well charge-discharge technique were utilized to conduct investigation both in the absence as well exist of phytic acid (PA) as an inhibitor. In addition, utilizing X-ray diffraction (XRD) and scanning electron microscope (SEM) techniques were carried out for further investigations. Results obtained indicated that PA is an efficient inhibitor for Pb-2 % In as anode in 4 M H2SO4 solution. The inhibitory effectiveness (η%) for Pb-2 % In alloy rises with a rising dose of PA and also rises with rising temperature. The lead acid battery's anode was well enhanced due to the highest inhibition efficiency (≈ 97.3 %), which has been attained in the existence of 1 × 10−3 M of PA inhibitor in 4 M H2SO4 at a temperature of 35 °C. The presence of an adsorbed film from PA was confirmed by SEM studies of the electrode exterior side. One might conclude that an increase in inhibitory effect η% with temperature is an indication that inhibitor molecules are being chemically deposited on the exterior side of Pb-2 %In alloy. DFT data confirms the suggested action of PA towards the inhibition effect and enhancement of the charge-discharge performance of the studied alloy. These findings shed light on the potential of utilizing phytic acid as an effective additive for Pb-2 %In alloy anodes in lead-acid battery applications.

A method for estimating the state of health of lithium-ion batteries based on physics-informed neural network

Data-driven methods have been widely used to estimate the State of health (SOH) of Lithium-Ion batteries (LIBs). However, these methods lack interpretability. In response to this issue, this article proposes a method called Physics-informed neural network (PIFNN) to enhance the interpretability of predictions made by a feedforward neural network (FNN). First, the features are extracted from incremental capacity (IC) curves and differential temperature curves, which can characterize battery aging from different perspectives. Specifically, the peaks of the IC curves (P-IC) reflect the electrochemical reactions that occur during the charge-discharge processes of LIBs. The decline of the P-IC is related to the loss of active materials in LIBs, which is a major cause of the decrease of the SOH. This article converts the monotonous relationship between the P-IC and the SOH into physical constraints to guide the “learning process” of the model. In the prediction process, a physics-constrained secondary “training” is applied to the FNN predictions to further enhance interpretability and improve prediction accuracy. The feasibility of the proposed method is validated using the Oxford and NASA battery datasets. The results indicate that PIFNN effectively improves prediction accuracy and reduces errors to below 1.5 %.

Toward high stability of O3‐type NaNi1/3Fe1/3Mn1/3O2 cathode material with zirconium substitution for advanced sodium‐ion batteries

AbstractWe successfully synthesized a series of O3‐type NaNi1/3Fe1/3Mn1/3−xZrxO2 (x = 0, 0.01, 0.02, 0.04) cathode materials by the solid‐state reaction method. Energy dispersion spectroscopy, X‐ray diffraction (XRD), and X‐ray photoelectron spectroscopy results confirmed the successful incorporation of Zr elements into the lattice to substitute Mn. Due to the introduction of Zr4+, the crystal structure modulation of O3‐NaNi1/3Fe1/3Mn1/3O2 has been realized. By increasing the Zr4+ content, the width of the sodium diffusion layer expands, thereby facilitating the diffusion of sodium ions. Consequently, the material exhibits a remarkable enhancement in high‐rate capability. At the same time, increasing the Zr4+ content results in a notable decrease in both the average bond length of TM−O and the thickness of the TMO6 octahedron in the transition metal layer, resulting in a significant improvement in the cycling performance and structural stability of the cathode material. Additionally, the in‐situ XRD results demonstrate that the optimized cathode composition of O3‐NaNi1/3Fe1/3Mn1/3–0.02Zr0.02O2 (NFMZ2) undergoes a reversible phase transition of O3 → O3 + P3 → P3 → O3 + P3 → O3 during the charge–discharge process.

The transport property of CuCl under high pressure

The transport property of CuCl powder was investigated by AC impedance spectroscopy under high pressure. Each parameter varies abnormally at the pressure points of phase transitions. Under compression, the charge carrier changes from ion (F4‾3m) to electron (Pa3‾) and then back to ion (Fm3‾m). To the F4‾3m and the Fm3‾m phases, compression makes the charge-discharge process easier and the grain and grain boundary resistance decreased. To the Pa3‾ phase, the lattice strain increasing with the pressure increasing causes the activation enthalpy decreased and the electronic transport easier.