Change In Open Circuit Voltage Research Articles

High ion exchange capacity perfluorosulfonic acid resine proton exchange membrane for high temperature applications in polymer electrolyte fuel cells

High-temperature proton exchange membrane fuel cells (HT-PEMFCs) have attract much attention from academic and industry, which can improve the catalyst activity, reduce Pt loading, enhance CO tolerance, and simplify water and heat management. High-temperature proton exchange membrane (HT-PEM) is the key component for HT-PEMFCs. Here, we provide an investigation of newly developed HT-PEM to evaluate its properties and performances in fuel cells above 90 °C. The HT-PEM exhibits an excellent proton conductivity of 136.1 mS cm−1 at 90 °C and 95% RH, and remarkable power density of 0.95 Wcm−2 at 105 °C and 80% RH. The stability and durability of HT-PEM are studied with varied testing methods. After the continuous operation at open circuit voltage (OCV) for 500 h and continuous dry-wet circulation for 20000 cycles at 90 °C, negligible change of OCV and hydrogen permeation current density are recorded, indicating good chemical and mechanical stability for HT-PEM. The improved property and performance originate from the new PFSA base material and improved morphology, in which the larger ionic clusters and continuous proton-transfer channels contribute to the superior performance, and the high glass transition temperature (Tg∼132 °C) induces good stability.

A novel method for constructing the relationships between state of charge and open-circuit voltage of lithium-ion battery under different temperatures with reduced test time

The equivalent circuit models (ECMs) have been extensively applied to estimate the state-of-charge (SOC) for lithium-ion batteries. And it is significant for ECMs to establish the relationship between the open-circuit voltage (OCV) and SOC. The accurate relationship is usually obtained from the incremental OCV (IO) test, which is time-consuming for each OCV test point. To overcome this shortcoming, a novel method for obtaining the relationship is proposed to save test time. Firstly, five OCV test points of the IO tests are used under different temperatures, and the OCV change trend along the SOC is acquired from the low-current OCV test at room temperature, from which the feature points are extracted by the Douglas-Peucker algorithm to express the OCV change trends. Finally, the OCV test points are connected by moving feature points twice to construct the SOC-OCV curves under different temperatures with fewer OCV test points. The SOC estimations of two different lithium-ion batteries are achieved based on the second-order RC ECM using the adaptive extended Kalman filter. The results indicate that the SOC estimations are more accurate in a wide temperature range compared to the traditional method while the time for OCV tests is reduced by at least 50%.

Electrode Ionomer Accelerated Stress Test Applied to High Oxygen Permeability Ionomer in Fuel Cells

Perfluorosulfonic acid (PFSA) polymer electrolytes are widely used in proton exchange membrane (PEM) fuel cell fabrication for the membrane separator and the electrode binder. The PEM serves to electrically insulate the cathode catalyst layer (CCL) from anode catalyst layer (ACL), provide proton conduction between both CCL and ACL, as well as prevent gas crossover. PFSA ionomers are also used in the CCL and ACL to mechanically bind the catalyst particles into thin-films, provide proton conduction between the PEM and catalyst surface, and produce a high proton reactant concentration at the oxygen reduction reaction catalyst. Despite their versatility to be used as a membrane and catalyst binder, the typical PFSA ionomers pose challenges due to the high oxygen transport resistance that is introduced by the thin ionomer films over the catalyst. In recent years, novel high oxygen permeability ionomers (HOPIs) have been developed as the successor to the traditional Nafion™ PFSA ionomers. Despite their remarkable results as a catalyst binder due to their increased oxygen transport rates, less is known regarding their degradation and functional lifetime. Although accelerated stress tests (ASTs) for platinum (Pt)/Pt-alloy catalysts, carbon supports, and membranes are well-established and commonly applied, there is no standard and easily implemented AST for electrode ionomers. One challenge is that membrane ASTs usually quantify the fluoride emission rate (FER) to assess chemical degradation, which is difficult to apply for electrode PFSA ionomer when also using a PFSA membrane because the FER is overwhelmed by membrane signal. In addition, changes in OCV and H2 crossover are not directly indicative of electrode ionomer degradation. Furthermore, concomitant degradation of the catalyst and support can interfere with interpreting electrode ionomer degradation. Here we present an effective and easily applied electrode ionomer chemical AST protocol that can be used to evaluate degradation in the functionality of the electrode ionomer. The approach borrows the chemical AST conditions of the chemical membrane AST’s open circuit voltage (OCV) hold and avoids excessive potential cycling to minimize catalyst and support degradation that will elicit changes in electrode properties separate from ionomer degradation. During the AST, we measure the cathode’s proton conduction resistance, oxygen permeability, and electrochemically surface area (ECSA) to evaluate the degradation of the ionomer’s functionality. Thus, this protocol can be used to assess if more complex and time consuming analyses of ionomer durability are needed as new chemistries emerge. Here we present results of this AST to both conventional PFSA ionomers and HOPIs.

Research on a fast detection method of self-discharge of lithium battery

The self-discharge of the battery refers to the phenomenon that the capacity of the battery decreases after the battery is charged and placed in the open-circuit state for a period of time, which is the holding ability of the stored electricity of the battery under certain conditions. When the self-discharge of the battery is too large or the self-discharge consistency of the cells in the battery pack is poor, it will affect the cruising range of the new energy electric vehicle and the overall energy storage system. To quickly detect the self-discharge rate of lithium batteries, this paper proposes a rapid detection method to characterize the self-discharge rate by OCV (Open Circuit Voltage) in a short period and at the cell level based on the change of OCV during the battery resting process. This method removes the influence of lithium battery polarization on subsequent analysis by selecting the OCV of the appropriate time. After analyzing the OCV threshold corresponding to each cell from the experimental data obtained by screening, the OCV difference between 12 h and 24 h during the resting process is compared with the corresponding OCV threshold. The ratio of thresholds is normalized. Through the normalized results, the self-discharge rate of each cell is analyzed, and the cell with a larger self-discharge rate is obtained. After that, the self-discharge analysis results within 24 h, and the self-discharge analysis results in the complete resting process for 30d are compared and verified, it is concluded that the results detected by this method are correct, indicating that the self-discharge rapid detection method has high accuracy.

Joint estimation method for maximum available energy and state-of-energy of lithium-ion battery under various temperatures

Accurate estimation for state-of-energy (SOE), defined as the ratio of residual available energy to maximum available energy, is an important task in battery management system. Nevertheless, the reduction in maximum available energy caused by battery degradation may lower SOE estimation accuracy, which is almost ignored in existing SOE estimation algorithms. To ensure precise SOE prediction over battery's whole lifetime, a joint estimation method for maximum available energy and SOE is proposed in this paper. Firstly, the parameters of the first-order RC battery model are online identified by forgetting factor recursive least square, where rough SOE is inferred directly from identified open-circuit-voltage (OCV). Considering OCV change at adjacent sampling time, a third-order extended Kalman filter is established to correct OCV and estimate maximum available energy with identified parameters and rough SOE. Finally, the predicted maximum available energy is further transmitted into adaptive extended Kalman filter to estimate SOE. The feasibility, prediction accuracy and robustness ability are verified with Federal Urban Driving Schedule tests under the temperature range of 0 °C–50 °C. Validation results indicate that the proposed joint estimation method can still provide accurate maximum available energy and SOE prediction results even though there exist various forms of interferences.

A Numerical Study on the Impact of Cathode Catalyst Layer Loading on the Open Circuit Voltage in a Proton Exchange Membrane Fuel Cell

The open circuit voltage (OCV) in a proton exchange membrane fuel cell (PEMFC) is typically recorded as being approximately 300 mV lower than the equilibrium voltage computed by the Nernst equation. While a number of causes have been proposed, the voltage drop is generally attributed to the oxidation of crossover hydrogen in the cathode. A single phase, through-the-channel model is presented that includes hydrogen transport across the membrane, an empirical model for the hydrogen oxidation reaction (HOR) fit to experimental data obtained at high potentials and a multi-step kinetic model to describe the oxygen reduction reaction (ORR). Model predictions were compared to experimentally obtained OCVs and the results show that the model is capable of capturing the experimentally observed changes in OCV with platinum loading, as well as fuel cell performance; and that, at low Pt loadings, small quantities of unreacted hydrogen leave the cathode because the HOR is kinetically limited by oxide blocking and anion adsorption. A parametric study is used to show that a minimum OCV is achieved at ultra-low loadings. Results also show that only a multi-step ORR model can simultaneously capture polarization data and the OCV.

Real‐time identification of partnership for a new generation of vehicles battery model parameters based on the model reference adaptive system

Partnership for a new generation of vehicles (PNGV) model is a conventional battery equivalent circuit model (ECM). However, identifying the best parameters for this model is a challenge. In this study, the PNGV model is transformed into a directly identifiable difference equation to identify its parameters. Subsequently, the model reference adaptive system (MRAS) is used to realize the real-time identification of the model parameters. The identification accuracy of the MRAS is found to be superior to that of the recursive extended least square algorithm. For a single hybrid pulse power characterization (HPPC), the PNGV model identified by the MRAS can achieve a high-precision terminal voltage estimation. For lithium iron phosphate, lithium titanate, and nickel-metal hydride batteries, the root mean square errors are 0.024, 0.048, and 0.020 V, respectively. Besides, the real-time state of charge (SOC) estimation can be realized by the identified open-circuit voltage (OCV). The average errors of the three batteries are only −0.02, −0.01, and −0.01, respectively. Since the PNGV model has a capacity of describing the change of OCV with the current accumulation effect, the model is only suitable for simulating single HPPC or positive-negative pulses with equal amplitude and not for other current pulses. This is a major drawback of the PNGV model. The real-time PNGV model parameters identification method proposed in this study can provide a solid foundation for various state estimation of a battery. Novelty Statement Transformation of the PNGV model into a difference equation that can be directly identified. Real-time identification of the PNGV model parameters via the MRAS. The identified OCV realized the real-time SOC estimation and discussed the deficiencies of the PNGV model.

Self-Powered Carbon Nanotube Yarn for Acceleration Sensor Application

Accelerometers are indispensable for detecting accelerating forces in automotive electronic systems. Although several accelerometers have been developed, they are still unstable for vehicle dynamics' applications in the low-frequency range (0-20 Hz). Here, we report a novel type of accelerometer based on a coiled carbon nanotube (CNT) yarn as a self-powered and low-frequency range-covered acceleration sensor. The proposed sensor is designed in a compact fiber-like structure for practical applications. Open-circuit voltage (OCV) signals are consistently generated during the stretch-and-release process of the coiled CNT yarn by the applied sinusoidal accelerations, and the OCV changes increase linearly with increasing acceleration from 4.84 to 48.37 m/s <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . Our accelerometer exhibits excellent dynamic sensing performance in the low-frequency range compared with commercial accelerometers. In an application as a CNT yarn device configured with a mass load, the OCV change is linearly proportional to the applied acceleration. When our accelerometer is attached to a seatbelt in a vehicle, it generates OCV changes from the movement of the body mass underlying a certain acceleration change. Given its excellent sensing performance, the CNT yarn acceleration sensor could further be developed for practical applications, such as seatbelts and car seats with fabric and textile.

A new method to estimate the state of charge of the green battery

Green batteries have attracted great attention due to the characteristics of its high performance and non-pollution. In order to understand the working condition of the batteries and get a better estimation effect on the state of charge (SoC), the following works had been done in NMC18650 lithium ion battery. Firstly, the hybrid pulse power characteristic (HPPC) test was carried out on the battery with different currents. The extended Kalman filter (EKF) was used to estimate the SoC of the battery based on combined model and Thevenin model whose parameters were identified in advance; furthermore, the estimation results of the two models were compared. Secondly, an improved open circuit voltage (OCV) based method was proposed. Its improvements were as follows: the changes of OCV on battery were recorded during the current interruption, and it was assumed that the OCV had been restored to a certain degree if the change of OCV did not exceed 0.001V in 10s. Finally, two new improved methods were proposed based on the combined model, and the estimation effects of the above methods were compared under dynamic condition. The results showed that the accuracy of the Thevenin model was slightly higher than that of the combined model, and the accuracies of the two improved methods were both improved. Especially the second improved method had the least error and the best adaptability; the maximum error under dynamic conditions was 3.07%, and the average error was less than 1%, which only accounted for 22.46% of the un- improved. The improved OCV based method proposed in this study is applied to the SoC estimation of batteries, which greatly improves the accuracy of the estimation; moreover, the method is easy to implement and suitable for estimating SoC in real time.

Multi-temperature state-dependent equivalent circuit discharge model for lithium-sulfur batteries

Abstract Lithium-sulfur (Li-S) batteries are described extensively in the literature, but existing computational models aimed at scientific understanding are too complex for use in applications such as battery management. Computationally simple models are vital for exploitation. This paper proposes a non-linear state-of-charge dependent Li-S equivalent circuit network (ECN) model for a Li-S cell under discharge. Li-S batteries are fundamentally different to Li-ion batteries, and require chemistry-specific models. A new Li-S model is obtained using a ‘behavioural’ interpretation of the ECN model; as Li-S exhibits a ‘steep’ open-circuit voltage (OCV) profile at high states-of-charge, identification methods are designed to take into account OCV changes during current pulses. The prediction-error minimization technique is used. The model is parameterized from laboratory experiments using a mixed-size current pulse profile at four temperatures from 10 °C to 50 °C, giving linearized ECN parameters for a range of states-of-charge, currents and temperatures. These are used to create a nonlinear polynomial-based battery model suitable for use in a battery management system. When the model is used to predict the behaviour of a validation data set representing an automotive NEDC driving cycle, the terminal voltage predictions are judged accurate with a root mean square error of 32 mV.

Degradation of Solid Electrolyte Interphase By Phosphorus Pentafluoride Generated By Thermal Decomposition of Lithium Hexafluorophosphate

Introduction The solid electrolyte interphase (SEI) on the negative electrode is known to play a key role on cell safety. Namely, if the SEI layer is damaged at high temperatures, electrode/electrolyte decomposition is induced along with cell heating, which can trigger thermal runaway. Lithium hexafluorophosphate (LiPF6) is known be thermally decomposed (LiPF6 → LiF + PF5) over 70oC. Here, the as-generated phosphorus pentafluoride (PF5) is known to react with organic solvents such as ethylene carbonate (EC) at high temperatures.1 It is thus very likely that PF5 can attack the organic and/or inorganic components of SEI layer to deteriorate the passivating ability of SEI layer. In this work, to confirm the SEI damage by PF5 attack, the open-circuit voltage (OCV) was monitored while the Li/SiO cells, wherein the concentration of PF5 precursor (LiPF6) was varied, were stored at 85oC. A more serious SEI damage is expected with a larger LiPF6 loading. As a PF5 scavenger, tris(2,2,2-trifluoroethyl) phosphite (TTFP) was added into the electrolyte solution. The former (PF5) is a strong Lewis acid, while the latter is Lewis base, such that a strong complex formation is expected from the two.2 Experimental Two different experiments were performed. (1) The 2032-type coin cells with SiO working electrode, Li counter electrode and electrolyte (1.3 M LiPF6 EC:DEC (3:7, v/v)) were assembled, and cycled 5 times to obtain a stable SEI layer on the SiO electrode. The cells were then dismantled and re-assembled by adding different electrolyte (0.0 M, 0.7 M and 1.3 M LiPF6 in EC:DEC (3:7, (v/v)). The re-assembled cells were stored at 85oC for 1 day, while the OCV was monitored. (2) The 2032-type coin cells with SiO working electrode, Li counter electrode and two different electrolyte solution (1.3 M LiPF6 in EC:DEC (3:7, v/v) and 1.3 M LiPF6 in EC:DEC (3:7, v/v) + 5% TTFP)) were assembled, and cycled 5 times to obtain a stable SEI layer on the SiO electrode. The same storage experiment was performed. The passivation ability of SEI layer was assessed by monitoring the OCV values and the chemical composition of SEI layer was analyzed by using XPS. Results and Discussion Fig. 1 (a) shows the OCV profiles obtained from the Li/SiO cells during the 85oC storage. As is seen, the OCV values increase at a faster rate with an increase in LiPF6 concentration. The OCV increase signifies the oxidation (self-discharge) of SiO electrode, which in turn indicates the damage and loss of passivating ability of SEI layer.3 The SEI damage is resulted from PF5 attack, which is generated by thermal decomposition of LiPF6. Fig. 1 (b) compares the OCV change for two Li/SiO cells. The cell containing TTFP shows a much slower OCV increase, illustrating that the SEI layer is rather intact even upon 85oC exposure. The SEI damage by PF5 attack was marginal due to the scavenging action of TTFP for PF5. Reference 1. S. E. Sloop, J. B. Kerr, and K. Kinoshita, J. Power Sources, 119-121, 330 (2003). 2. S. S. Zhang, K. Xu, and T. R. Jow, Electrochemical and Solid-state Letters, 5, A206 (2002). 3. H. Park, T. Yoon, J. Mun, J. H. Ryu, J. J. Kim, and S. M. Oh, J. Electrochem. Soc., 160, A1539 (2013). Fig ure 1 . The OCV profiles obtained from the Li/SiO cells that were stored at 85oC. (a) The concentration of LiPF6 was varied in the electrolyte solutions, (b) TTFP was added into the electrolyte solution in one cell. Figure 1

Comprehensive study of the influence of aging on the hysteresis behavior of a lithium iron phosphate cathode-based lithium ion battery – An experimental investigation of the hysteresis

In this work a detailed investigation of the hysteresis behavior of the open circuit voltage (OCV) in a lithium iron phosphate (LiFePO4) cathode-based lithium-ion cell is presented. For the first time the hysteresis behavior of the OCV in a LiFePO4 cell is investigated in detail, taking the aging state of the cells into account as a fundamental factor. Tests were carried out in a time window of more than two years on cells in different aging states. The dependency of the major and minor loops of the OCV on temperature, current rate, short-term history and aging are shown and deeply discussed. The results show that the characteristics of the hysteresis of the OCV change completely during battery lifetime, not only concerning the major OCV boundaries but also regarding the single minor loops obtained through partial charge/discharge processes. The paper discusses the results considering different approaches presented in the literature published by date, and addresses the necessity of understanding the physic-chemical behavior of the cell in order to correctly determine the battery state in the application.

Capacity-loss diagnostic and life-time prediction in lithium-ion batteries: Part 1. Development of a capacity-loss diagnostic method based on open-circuit voltage analysis

Effective capacity-loss diagnosis and life-time prediction are the foundations of battery second-use technology and will play an important role in the development of the new energy industry. Of the two, the capacity-loss diagnostic, as a precondition of the life-time prediction, needs to be studied first. Performing a capacity-loss diagnosis for an aging cell consists of finding the decisive degradation mechanisms for the cell's capacity degradation. Because a cell's capacity just equals the span of the open-circuit voltage (OCV), when suspect degradation mechanisms affect a cell's capacity, they will leave corresponding and particular clues in the OCV curve. Taking a cell's OCV as the diagnostic indicator, a multi-mechanistic and non-destructive diagnostic method is developed in this paper. To establish an unambiguous relationship between OCV changes and the combinations of the decisive mechanisms, all the possible OCV changes under various aging situations are systematically analyzed based on a novel simultaneous coordinate system, in which the effects of each suspect capacity-loss mechanism on the OCV curve can be clearly represented. As a summary of the analysis results, a straightforward diagnostic flowchart is presented. By following the flowchart, an aging cell can be diagnosed within three steps by observation of the OCV changes.

In-Situ Temperature Sensing of SOFC during Anode Reduction and Cell Operations Using a Multi-Junction Thermocouple Network

Temperature driven performance degradations is one of the major problems that impedes the successful commercialisation of Solid Oxide Fuel Cell (SOFC) technology. To mitigate such degradations as well as to further enhance stack’s performance, it is very important to understand the temperature distribution of a SOFC stack while in operation. Researches for experimental measurement of the temperature distribution are very limited in literature. The available efforts are also confined for measuring temperature in both (air/ fuel) channels and they mostly do not measure the temperature from a SOFC electrodes, which is more desirable than gas temperature measurement for investigating cells’ behaviour and the correlation to the stack’s performance. Further, the most widely adapted method for stack temperature measurement is to insert commercial thermocouples inside a fuel cell stack, which introduce disturbance to the normal operation of a stack and impose significant limitations on the number of independent point within a stack where temperature can be measured. Therefore, the in-situ cell temperature monitoring is a topical research area where a technical challenge is necessary. The proposed thermocouple network architecture can independently measure the temperature at N2 number of points with only 2N number of thermo-elements/ external wires. Hence, it requires much less number of external wires than a set of thermocouples require for the same number of independent temperature measuring points. Reduction in the number of external wires requirement enables to measure the temperature with greater spatial resolution and lower disturbance to the normal operation of the cell/ stack. In addition to measuring the temperature, the propose thermocouple network can simultaneously collect the current from the electrodes while measuring temperature. The authors have experimentally validated and confirmed these abilities prior to applying the thermocouple network for in-situ temperature monitoring presented below. A thermocouple network was fabricated by weaving K-type thermocouple wires (ϕ 0.25mm), and then spot welding its intersections to form a mesh where each spot welded point acts as a temperature measuring point. The intersection of 3 Alumel (Ni: Al: Mn: Si – 95:2:2:1 by wt.) and 3 Chromel (Ni:Cr – 90:10 by wt.) wires formed 9 independent temperature measuring points with a pitch of about 10mm. Using this thermocouple network, authors measured the cathode temperature during an anode reduction process and then measured the same during normal cell operation of a commercial SOFC test cell (50mmx50mm, NextCell-5) while the air/fuel ratio varies. In addition, Open Circuit Voltage (OCV) was also measured during the operation. The thermocouple network was in direct contact with the cathode and hence, measured the cathode temperature. The gas temperature was also measured simultaneously using a commercial K-type thermocouple from 5 mm adjacent to the electrode to investigate how effectively the gas temperature can represent the electrode’s temperature of a cell. Hydrogen and Air flow rates were altered to investigate cell’s response in terms of OCV change and temperature change. The measurements showed that the thermocouple network on cathode was very sensitive to even a trivial temperature changes whilst the commercial thermocouple adjacent to the cell was almost non-responsive to most of subtle temperature changes that occurred on the cell. During the monitoring, dramatic temperature fluctuation and uneven temperature distribution were detected during the anode reduction process. A correlation between the OVC and the cell temperature was also investigated.

Influence of Gas Flow Rate on Performance of H 2 S /Air Solid Oxide Fuel Cells with MoS2 ­ NiS ­ Ag Anode

Performance of a solid oxide fuel cell with the configuration of /yttria-stabilized zirconia/Pt, air is dependent on anode and cathode compartment gas flow rates. The cell open-circuit voltage (OCV) was independent of air flow rate but increased with increasing flow rate. A linear relationship existed between OCV and the logarithm of flow rate. Increasing the flow rate increased the exchange rate of reaction products and feed at the anode catalyst, thereby decreasing the local concentration of reaction products and increasing the local concentration of hence, OCV increased from the Nernst effect. The magnitude of the change in OCV with temperature was consistent with calculated values based on reaction equilibria. It was found that increasing either or both air flow rate and flow rate improved current-voltage and power density performance. The results were consistent with improved gas diffusion in the cathode with increasing air flow rate, and with both improved gas diffusion in anode and increased concentration of anodic electroactive species with increasing flow rate. © 2003 The Electrochemical Society. All rights reserved.

Influence of electrode materials on open-circuit voltage profiles with a temperature difference for a thermocell using a Br 2/Br −-redox reaction

We investigated the dependence of open-circuit voltage (OCV) on temperature difference, δT, between hot and cold electrodes for a Br 2/Br −-redox thermocell with carbon materials having a large specific surface area (Maxsorb) as electrodes and 3.36 M KBr aqueous electrolyte containing Br 2 and compared it with that for thermocells with Pt electrodes. The rate of change in OCV with δT largely changed at a certain value of δT (critical δT). We assumed that the OCV change with δT can be expressed by quadratic or linear equations of δT differently in the regions above and below critical δT. The influence of Br 2 concentration on thermoelectric power |dE/d T| was smaller for Maxsorb electrode cells than for Pt electrode cells, and the |d E/d T| for Maxsorb electrodes was smaller than that for Pt electrodes above the critical δT. This may be related to differences in the amount of Br 2 adsorption at the reaction sites on the electrode surface. We found hysteresis in the OCV change with δT for both electrode systems when δT was increased and decreased. The hysteresis appears to depend on cell configuration.

Electrochemical Behavior of Amorphous V 2 O 5 ‐ TeO2 in Lithium Cells

Amorphous was fabricated by rapid quenching of melts. The open circuit voltage (OCV) of with 85–50 mole percent content in nonaqueous lithium cells was studied. During discharge, showed two slopes for OCV changes. The absolute value of the first slope decreased with an increase in the content. The Li insertion amount at the bending point of the OCV slope also increased with an increase in the content. These tendencies are explained by assuming that is a mixture of and .

The Silver/Silver Chloride/Chlorine Solid Electrolyte Cell

A solid electrolyte cell has been developed in which the chlorine is furnished by the dissociation of potassium tetrachloroiodide, . These cells can be assembled into batteries which are extremely stable and compact and which deliver currents in the microampere range. The dissociation characteristics of the cathode salt influence the shelf‐life, temperature dependence of the open‐circuit voltage (OCV), and the change of OCV with aging. The ionic conductivity of the electrolyte controls the internal resistance of the battery and its temperature dependence. The shelf‐life, OCV, and temperature dependence of OCV are strongly dependent on the cathode atmosphere since this can influence the electronic conduction of the electrolyte.