Transmission, Distribution & Storage

Hydrogen is considered a secondary source of energy commonly referred to as an energy carrier. It has the highest energy content when compared to other common fuels by weight having great potential for further development. Hydrogen can be produced from various domestic resources but based on the fossil resource conditions in China coal-based hydrogen energy is considered to be the most valuable because it is not only an effective way to develop clean energy but also a proactive exploration of the clean usage of traditional coal resources. In this article the sorption-enhanced water–gas shift technology in the coal-to-hydrogen section and the hydrogen-storage and transport technology with liquid aromatics are introduced and basic mechanisms technical advantages latest progress and future R&D focuses of hydrogen-production and storage processes are listed and discussed. As a conclusion after considering the development frame and the business characteristics of CHN Energy Group a conceptual architecture for developing coal-based hydrogen energy and the corresponding supply chain is proposed.

Hydrogen was doped in austenitic stainless steel (ASS) 316L tensile samples produced by the laser-powder bed fusion (L-PBF) technique. For this aim an electrochemical method was conducted under a high current density of 100 mA/cm2 for three days to examine its sustainability under extreme hydrogen environments at ambient temperatures. The chemical composition of the starting powders contained a high amount of Ni approximately 12.9 wt.% as a strong austenite stabilizer. The tensile tests disclosed that hydrogen charging caused a minor reduction in the elongation to failure (approximately 3.5% on average) and ultimate tensile strength (UTS; approximately 2.1% on average) of the samples using a low strain rate of 1.2 × 10⁻⁴ s⁻¹. It was also found that an increase in the strain rate from 1.2 × 10⁻⁴ s⁻¹ o 4.8 ×10⁻⁴ s⁻¹ led to a reduction of approximately 3.6% on average for the elongation to failure and 1.7% on average for UTS in the pre-charged samples. No trace of martensite was detected in the X-ray diffraction (XRD) analysis of the fractured samples thanks to the high Ni content which caused a minor reduction in UTS × uniform elongation (UE) (GPa%) after the H charging. Considerable surface tearing was observed for the pre-charged sample after the tensile deformation. Additionally some cracks were observed to be independent of the melt pool boundaries indicating that such boundaries cannot necessarily act as a suitable area for the crack propagation.

Many advanced steels are based on tempered martensitic microstructures. Their mechanical strength is characterized by fine sub-grain structures with a high density of free dislocations and metallic carbides and/or nitrides. However the strength for practical use has been limited mostly to below 1400 MPa owing to delayed fractures that are caused by hydrogen. A literature survey suggests that ε-carbide in the tempered martensite is effective for strengthening. A preliminary experimental survey of the hydrogen absorption and hydrogen embrittlement of a tempered martensitic steel with ε-carbide precipitates suggested that the proper use of carbides in steels can promote a high resistance to hydrogen embrittlement. Based on the surveys martensitic steels that are highly resistant to hydrogen embrittlement and that have high strength and toughness are proposed. The heuristic design of the steels includes alloying elements necessary to stabilize the ε-carbide and procedures to introduce inoculants for the controlled nucleation of ε-carbide.

This research introduces a ‘Hydrogen Interconnector System’ (HIS) as a novel method 7 for transporting electrical energy over long distances. The system takes electricity from 8 stranded renewable energy assets converts it to hydrogen in an electrolyser plant transports 9 hydrogen to the demand centre via pipeline where it is reconverted to electricity in either a 10 gas turbine or fuel cell plant. This paper evaluates the competitiveness of the technology with 11 High Voltage Direct Current (HVDC) systems calculating the following techno-economic 12 indicators; Levelised Cost Of Electricity (LCOE) and Levelised Cost Of Storage (LCOS). The 13 results suggest that the LCOE of the HIS is competitive with HVDC for construction in 2050 14 with distance beyond 350km in case of all scenarios for a 1GW system. The LCOS is lower 15 than an HVDC system using large scale hydrogen storage in 6 out of 12 scenarios analysed 16 including for construction from 2025. The HIS was also applied to three case studies with 17 the results showing that the system outperforms HVDC from LCOS perspectives in all cases 18 and has 15-20% lower investment costs in 2 studies analysed.

In this paper comparison studies of the hydrogen effect on the structural and phase state deformation behavior and mechanical properties of the fine- (average grain size 4 µm) and ultrafine-grained (average element size 0.3 and 0.4 µm) Zr–1wt.%Nb (hereinafter Zr–1Nb) alloy under tension at temperatures in the range of 293–873 K were conducted. The formation of an ultrafine-grained structure is established to increase the strength characteristics of the Zr–1Nb alloy by a factor of 1.5–2 with a simultaneous reduction of its resistance to the localization of plastic deformation at the macro level and the value of deformation to failure. The presence of hydrogen in the Zr–1Nb alloy in the form of a solid solution and hydride precipitates increases its resistance to the localization of plastic deformation at the macro level if the alloy has an ultrafine-grained structure and decreases if the structure of the alloy is fine-grained. In the studied temperature range the Zr–1Nb alloy in the ultrafine-grained state has a higher resistance to hydrogen embrittlement than the alloy in the fine-grained state.

Hydrogen embrittlement (HE) is one of the main limitations in the use of advanced high-strength steels in the automotive industry. To have a better understanding of the interaction between hydrogen (H) and a complex phase steel an in-situ method with plasma charging was applied in order to provide continuous H supply during mechanical testing in order to avoid H outgassing. For such fast-H diffusion materials only direct observation during in-situ charging allows for addressing H effects on materials. Different plasma charging conditions were analysed yet there was not a pronounced effect on the mechanical properties. The H concentration was calculated while using a simple analytical model as well as a simulation approach resulting in consistent low H values below the critical concentration to produce embrittlement. However the dimple size decreased in the presence of H and with increasing charging time the crack propagation rate increased. The rate dependence of flow properties of the material was also investigated proving that the material has no strain rate sensitivity which confirmed that the crack propagation rate increased due to H effects. Even though the H concentration was low in the experiments that are presented here different technological alternatives can be implemented in order to increase the maximum solute concentration.

The development of a hydrogen-based economy is the perfect nexus between the need of discontinuing the use of fossil fuels (trying to mitigate climate change) the development of a system based on renewable energy (with the use of hydrogen allowing us to buffer the discontinuities produced in this generation) and the achievement of a local-based robust energy supply system. However extending the use of hydrogen as an energy vector must still overcome challenging issues with the key issues being related to its storage. Cryogenic or pressurized storage is relatively expensive technically complex and presents important safety concerns. As a promising alternative the use of organic hydrogen carriers has been suggested in recent years. The ideal carrier will be an organic compound with a low melting point and low viscosity with a significant number of unsaturated carbon–carbon bonds in addition to being easy to hydrogenate and dehydrogenate. These properties allow us to store and transport hydrogen in infrastructures designed for liquid fuels thus facilitating the replacement of fossil fuels by hydrogen

The liquid organic hydrogen carriers (LOHC) are aromatic molecules which can be considered as an attractive option for the storage and transport of hydrogen. A considerable amount of hydrogen up to 7–8% wt. can be loaded and unloaded with a reversible chemical reaction. Substituted quinolines and pyridines are available from petroleum coal processing and wood preservation or they can be synthesized from aniline. Quinolines and pyridines can be considered as potential LOHC systems provided they have favorable thermodynamic properties which were the focus of this current study. The absolute vapor pressures of methyl-quinolines were measured using the transpiration method. The standard molar enthalpies of vaporization of alkyl-substituted quinolines and pyridines were derived from the vapor pressure temperature dependencies. Thermodynamic data on vaporization and formation enthalpies available in the literature were collected evaluated and combined with our own experimental results. The theoretical standard molar gas-phase enthalpies of formation of quinolines and pyridines calculated using the quantum-chemical G4 methods agreed well with the evaluated experimental data. Reliable standard molar enthalpies of formation in the liquid phase were derived by combining high-level quantum chemistry values of gas-phase enthalpies of formation with experimentally determined enthalpies of vaporization. The liquid-phase hydrogenation/dehydrogenation reaction enthalpies of alkyl-substituted pyridines and quinolines were calculated and compared with the data for other potential liquid organic hydrogen carriers. The comparatively low enthalpies of reaction make these heteroaromatics a seminal LOHC system.

The Aberdeen Vision Project could deliver CO2 savings of 1.5MtCO2/y compared with natural gas. A dedicated pipeline from St Fergus to Aberdeen would enable the phased transfer of the Aberdeen regional gas distribution system to 20% then 100% hydrogen.

The study has demonstrated that 2% hydrogen can be injected into the National Transmission System (NTS) at St Fergus and its distribution through the system into the gas distribution network. Due to unique regional attributes the Aberdeen region could lead the UK in the conversion to largescale clean hydrogen. A 200MW hydrogen generation plant is planned to suit 2% blend into the NTS followed by a build out to supply the Aberdeen gas networks and to enable low cost hydrogen transport applications.

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The UK has committed to significantly reduce greenhouse gas emissions by 2050 to help address climate change. Decarbonising heating is a key part of this and using hydrogen (H2) as a replacement to natural gas (NG) can help in achieving this. The objective of current research including HyDeploy is to demonstrate that NG containing levels of H2 beyond those currently allowed of 0.1 vol% (1000 ppm) [1] can be distributed and utilised safely and efficiently. Initial projects such as HyDeploy are studying the effects of introducing up to 20 vol% H2 in NG but later projects are considering using up to 100 vol% H2.

A key element in the safe operation of a modern gas distribution system is gas detection. However the addition of hydrogen to NG will alter the characteristics of the gas and the impact on gas detection must be considered. It is important that sensors remain sufficiently sensitive to the presence of hydrogen natural gas carbon monoxide (CO) and oxygen (O2) deficiency and that they don’t lead to false positive or false negative readings. The aim of this document is to provide a summary of the requirements for gas detection of hydrogen enriched natural gas for the gas distribution industry and other potentially interested parties. As such it is based on gas detectors presently used by the industry with the only major differences being the effects of hydrogen on the sensitivity of flammable gas sensors and the cross sensitivity of carbon monoxide gas sensors to hydrogen.

There is further information of gas detector concepts and technologies in the appendices.

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Without remorse fossil fuels have made a huge contribution to global development in all of its forms. However the recent scientific outlooks are currently shifting as more research is targeted towards promoting a carbon-free economy in addition to the use of electric power from renewable sources. While renewable energy sources may be a solution to the anthropogenic greenhouse gas (GHG) emissions from fossil fuel they are yet season-dependent faced with major atmospheric drawbacks which when combined with annually varying but steady energy demand results in renewable energy excesses or deficits. Therefore it is essential to devise a long-term storage medium to balance their intermittent demand and supply. Hydrogen (H2) as an energy vector has been suggested as a viable method of achieving the objectives of meeting the increasing global energy demand. However successful implementation of a full-scale H2 economy requires large-scale H2 storage (as H2 is highly compressible). As such storage of H2 in geological formations has been considered as a potential solution where it can be withdrawn again at the larger stage for utilization. Thus in this review we focus on the potential use of geological formations for large-scale underground hydrogen storage (UHS) where both conventional and non-conventional UHS options were examined in depth. Also insights into some of the probable sites and the related examined criteria for selection were highlighted. The hydrodynamics of UHS influencing factors (including solid fluid and solid–fluid interactions) are summarized exclusively. In addition the economics and reaction perspectives inherent to UHS have been examined. The findings of this study show that UHS like other storage systems is still in its infancy. Further research and development are needed to address the significant hurdles and research gaps found particularly in replaceable influencing parameters. As a result this study is a valuable resource for UHS researchers.

Titanium-based alloys are susceptible to hydrogen embrittlement (HE) a phenomenon that deteriorates fatigue properties. Ti-6Al-4V is the most widely used titanium alloy and the effect of hydrogen embrittlement on fatigue crack growth (FCG) was investigated by carrying out crack propagation tests in air and high-pressure H₂ environment. The FCG test in hydrogen environment resulted in a drastic increase in crack growth rate at a certain Δ K with crack propagation rates up to 13 times higher than those observed in air. Possible reasons for such behaviour were discussed in this paper. The relationship between FCG results in high-pressure H₂ environment and microstructure was investigated by comparison with already published results of cast and forged Ti-6Al-4V. Coarser microstructure was found to be more sensitive to HE. Moreover the electron beam melting (EBM) materials experienced a crack growth acceleration in-between that of cast and wrought Ti-6Al-4V

This report was created to ensure a deeper understanding of the role and commercial viability of energy storage in enabling increasing levels of intermittent renewable power generation. It was specifically written to inform thought leaders and decision-makers about the potential contribution of storage in order to integrate renewable energy sources (RES) and about the actions required to ensure that storage is allowed to compete with the other flexibility options on a level playing field.<br/>The share of RES in the European electric power generation mix is expected to grow considerably constituting a significant contribution to the European Commission’s challenging targets to reduce greenhouse gas emissions. The share of RES production in electricity demand should reach about 36% by 2020 45-60% by 2030 and over 80% in 2050.<br/>In some scenarios up to 65% of EU power generation will be covered by solar photovoltaics (PV) as well as on- and offshore wind (variable renewable energy (VRE) sources) whose production is subject to both seasonal as well as hourly weather variability. This is a situation the power system has not coped with before. System flexibility needs which have historically been driven by variable demand patterns will increasingly be driven by supply variability as VRE penetration increases to very high levels (50% and more).<br/>Significant amounts of excess renewable energy (on the order of TWh) will start to emerge in countries across the EU with surpluses characterized by periods of high power output (GW) far in excess of demand. These periods will alternate with times when solar PV and wind are only generating at a fraction of their capacity and non-renewable generation capacity will be required.<br/>In addition the large intermittent power flows will put strain on the transmission and distribution network and make it more challenging to ensure that the electricity supply matches demand at all times.<br/>New systems and tools are required to ensure that this renewable energy is integrated into the power system effectively. There are four main options for providing the required flexibility to the power system: dispatchable generation transmission and distribution expansion demand side management and energy storage. All of these options have limitations and costs and none of them can solve the RES integration challenge alone. This report focuses on the question to what extent current and new storage technologies can contribute to integrate renewables in the long run and play additional roles in the short term.

The hydrogen permeation coefficient (ϕ) is generally used as a measure to show hydrogen permeation ability through dense metallic membranes which is the product of the Fick’s diffusion coefficient (D) and the Sieverts’ solubility constant (K). However the hydrogen permeability of metal membranes cannot be analyzed consistently with this conventional description. In this paper various methods for consistent analysis of hydrogen permeability are reviewed. The derivations of the descriptions are explained in detail and four applications of the consistent descriptions of hydrogen permeability are introduced: (1) prediction of hydrogen flux under given conditions (2) comparability of hydrogen permeability (3) understanding of the anomalous temperature dependence of hydrogen permeability of Pd-Ag alloy membrane and (4) design of alloy composition of non-Pd-based alloy membranes to satisfy both high hydrogen permeability together with strong resistance to hydrogen embrittlement.

This paper reports a new approach for exposing materials including solar cell structures to atomic hydrogen. This method is dubbed Shielded Hydrogen Passivation (SHP) and has a number of unique features offering high levels of atomic hydrogen at low temperature whilst inducing no damage. SHP uses a thin metallic layer in this work palladium between a hydrogen generating plasma and the sample which shields the silicon sample from damaging UV and energetic ions while releasing low energy neutral atomic hydrogen onto the sample. In this paper the importance of the preparation of the metallic shield either to remove a native oxide or to contaminate intentionally the surface are shown to be potential methods for increasing the amount of atomic hydrogen released. Excellent damage free surface passivation of thin oxides is observed by combining SHP and corona discharge obtaining minority carrier lifetimes of 2.2 ms and J0 values below 5.47 fA/cm2. This opens up a number of exciting opportunities for the passivation of advanced cell architectures such as passivated contacts and heterojunctions.

Carbon materials such as graphene nanoflakes carbon nanotubes and fullerene can be widely used to store hydrogen and doping these materials with lithium (Li) generally increases their H2 -storage densities. Unfortunately Li is expensive; therefore alternative metals are required to realize a hydrogen-based society. Sodium (Na) is an inexpensive element with chemical properties that are similar to those of lithium. In this study we used density functional theory to systematically investigate how hydrogen molecules interact with Na-doped graphene nanoflakes. A graphene nanoflake (GR) was modeled by a large polycyclic aromatic hydrocarbon composed of 37 benzene rings with GR-Na-(H2 )n and GR-Na+ -(H2 )n (n = 0–12) clusters used as hydrogen storage systems. Data obtained for the Na system were compared with those of the Li system. The single-H2 GR-Li and GR-Na systems (n = 1) exhibited binding energies (per H2 molecule) of 3.83 and 2.72 kcal/mol respectively revealing that the Li system has a high hydrogen-storage ability. This relationship is reversed from n = 4 onwards; the Na systems exhibited larger or similar binding energies for n = 4–12 than the Li-systems. The present study strongly suggests that Na can be used as an alternative metal to Li in H2 -storage applications. The H2 -storage mechanism in the Na system is also discussed based on the calculated results.

The review presented herein is regarding the stress corrosion cracking (SCC) phenomena of carbon steel pipelines affected by the corrosive electrolytes that comes from external (E) and internal (I) environments as well as the susceptibility and tensile stress on the SCC. Some useful tools are presented including essential aspects for determining and describing the E-SCC and I-SCC in oil and gas pipelines. Therefore this study aims to present a comprehensive and critical review of a brief experimental summary and a comparison of physicochemical mechanical and electrochemical data affecting external and internal SCC in carbon steel pipelines exposed to corrosive media have been conducted. The SCC hydrogen-induced cracking (HIC) hydrogen embrittlement and sulfide stress cracking (SSC) are attributed to the pH and to hydrogen becoming more corrosive by combining external and internal sources promoting cracking such as sulfide compounds acidic soils acidic atmospheric compounds hydrochloric acid sulfuric acid sodium hydroxide organic acids (acetic acid mainly) bacteria induced corrosion cathodic polarization among others. SCC growth is a reaction between the microstructural chemical and mechanical effects and it depends on the external and internal environmental sources promoting unpredictable cracks and fractures. In some cases E-SCC could be initiated by hydrogen that comes from the over-voltage during the cathodic protection processes. I-SCC could be activated by over-operating pressure and temperature at flowing media during the production gathering storage and transportation of wet hydrocarbons through pipelines. The mechanical properties related to I-SCC were higher in comparison with those reviewed by E-SCC suggesting that pipelines suffer more susceptibility to I-SCC. When a pipeline is designed the internal fluid being transported (changes of environments) and the external environment concerning SCC should be considered. This review offers a good starting point for newcomers into the field it is written as a tutorial and covers a large number of basic standards in the area.

In order to facilitate the application of hydrogen energy and ensure its safety the compressed hydrogen storage tank on board needs to be full of hydrogen gas within 3 minutes. Therefore to meet this requirement the effects of refueling parameters on the filling time need to be investigated urgently. For the purpose of solving this issue a novel analytical solution of filling time is obtained from a lumped parameter model in this paper. According to the equation of state for real gas and dimensionless numbers Nu and Re the function relationships between the filling time and the refueling parameters are presented. These parameters include initial temperature initial pressure inflow temperature final temperature and final pressure. These equations are used to fit the reference data the results of fitting show good agreement. Then the values of fitting parameters are further utilized so as to verify the validity of these formulas. We believe this study can contribute to control the hydrogen filling time and ensure the safety during fast filling process.

In this paper the hydrogen supply to an open-cathode PEM fuel cell (FC) by using metal hydride (MH) storage and thermal coupling between these two components are investigated theoretically. One of the challenges in using MH hydrogen storage canisters is their limited hydrogen supply rate as the hydrogen release from MH is an endothermic reaction. Therefore in order to meet the required hydrogen supply rate high amounts of MH should be employed that usually suggests storage of hydrogen to be higher than necessary for the application adding to the size weight and cost of the system. On the other hand the exhaust heat (i.e. that is usually wasted if not utilised for this purpose) from open-cathode FCs is a low-grade heat. However this heat can be transferred to MH canisters through convection to heat them up and increase their hydrogen release rate. A mathematical model is used to simulate the heat transfer between PEMFC exhaust heat and MH storage. This enables the prediction of the required MH for different FC power levels with and without heat supply to the MH storage. A 2.5-kW open-cathode FC is used to measure the exhaust air temperature at different output powers. It was found that in the absence of heat supply from the FC to the MH canisters significantly higher number of MH canisters are required to achieve the required rate of hydrogen supply to the FC for sustained operation (specially at high power outputs). However using the exhaust hot air from the FC to supply heat to the MH storage can reduce the number of the MH canisters required by around 40% to 70% for power output levels ranging from 500 W to 2000 W.

Multiple-energy-fuelling stations which can supply several types of energy such as gasoline CNG and hydrogen could guarantee the efficient use of space. To guide the safety management of hybrid hydrogen–gasoline fuelling stations which utilize liquid hydrogen as an energy carrier the scale of gasoline pool fires was estimated using the hazard assessment tool Toxic Release Analysis of Chemical Emissions (TRACE). Subsequently the temperature and the stress due to temperature distribution were estimated using ANSYS. Based on the results the safety of liquid hydrogen storage tanks was discussed. It was inferred that the emissivity of the outer material of the tank and the safety distance between liquid hydrogen storage tanks and gasoline dispensers should be less than 0.2 and more than 8.5 m respectively to protect the liquid hydrogen storage tank from the gasoline pool fire. To reduce the safety distance several measures are required e.g. additional thermal shields such as protective intumescent paint and water sprinkler systems and an increased slope to lead gasoline off to a safe domain away from the liquid hydrogen storage tank

A new type of high strength corrosion-resistant magnesium alloy was prepared by adding 1% rare earth Gd to AM50 and then treated with hot extrusion method. The stress corrosion properties of the new materials in air pure water 0.5 mol/L NaCl and 0.5 mol/L Na2_SO₄ solution were studied by the slow strain rate tensile (SSRT) test in situ open circuit potential test Tafel curve test stereomicroscope SEM and EDS. The results showed the following. The stress corrosion sensitivity of the material in different environments was Na2_SO₄> NaCl > distilled water > air. According to the Tafel curves measured at 0 and 100 MPa the corrosion voltage decreased little and the corrosion current density increased rapidly under 100 Pa. This was because the film of the corrosion product ruptured to form a large cathode and a small anode which resulted in a large instantaneous corrosion current. The mechanism of hydrogen embrittlement and anodic dissolution together affected the stress corrosion behavior of the alloy. In distilled water hydrogen embrittlement played a major role while in NaCl and Na2_SO₄solution hydrogen embrittlement and anodic dissolution were both affected. The direct reason of the stress corrosion crack (SCC) samples’ failure was the cracks expanding rapidly at the bottom of pit which was caused by corrosion.

Hydrogen has been long known to provide a solution toward clean energy systems. With this notion many efforts have been made to find new ways of storing hydrogen. As a result decades of studies has led to a wide range of hydrides that can store hydrogen in a solid form. Applications of these solid-state hydrides are well-suited to stationary applications. However the main challenge arises in making the selection of the Metal Hydrides (MH) that are best suited to meet application requirements. Herein we discuss the current state-of-art in controlling the properties of room temperature (RT) hydrides suitable for stationary application and their long term behavior in addition to initial activation their limitations and emerging trends to design better storage materials. The hydrogen storage properties and synthesis methods to alter the properties of these MH are discussed including the emerging approach of high-entropy alloys. In addition the integration of intermetallic hydrides in vessels their operation with fuel cells and their use as thermal storage is reviewed.

The storage of hydrogen gas in underground lined rock caverns (LRCs) enables the implementation of the first fossil-free steelmaking process to meet the large demand for crude steel. Predicting the response of rock mass is important to ensure that gas leakage due to rupture of the steel lining does not occur. Analytical and numerical models can be used to estimate the rock mass response to high internal pressure; however the fitness of these models under different in situ stress conditions and cavern shapes has not been studied. In this paper the suitability of analytical and numerical models to estimate the maximum cavern wall tangential strain under high internal pressure is studied. The analytical model is derived in detail and finite element (FE) models considering both two-dimensional (2D) and three-dimensional (3D) geometries are presented. These models are verified with field measurements from the LRC in Skallen southwestern Sweden. The analytical model is inexpensive to implement and gives good results for isotropic in situ stress conditions and large cavern heights. For the case of anisotropic horizontal in situ stresses as the conditions in Skallen the 3D FE model is the best approach

This paper proposes the use of the Point Method (PM) to analyse Environmentally Assisted Cracking (EAC) processes in steels containing U-shaped notches. The PM a methodology included within the Theory of Critical Distances (TCD) has been extensively validated by many authors for the analysis of fracture and fatigue phenomena of different types of materials containing notches. However it has never been applied to other critical or subcritical cracking processes such as EAC or creep crack propagation.<br/>This work provides a PM-based analysis of EAC emanating from notches which is validated by testing CT notched specimens of X80 and S420 steels subjected to aggressive environments under hydrogen embrittlement conditions.<br/>The results reveal that the PM accurately predicts the crack propagation onset condition as well as the evolution of the material’s apparent EAC resistance.

This paper has experimentally proved that hydrogen accumulates in large quantities in metal-ceramic and pocket electrodes of alkaline batteries during their operation. Hydrogen accumulates in the electrodes in an atomic form. After the release of hydrogen from the electrodes a powerful exothermic reaction of atomic hydrogen recombination with a large energy release occurs. This exothermic reaction is the cause of thermal runaway in alkaline batteries. For the KSL-15 battery the gravimetric capacity of sintered nickel matrix of the oxide-nickel electrode as hydrogen storage is 20.2 wt% and cadmium electrode is 11.5 wt%. The stored energy density in the metal-ceramic matrix of the oxide-nickel electrode of the battery KSL-15 is 44 kJ/g and in the cadmium electrode it is 25 kJ/g. The similar values for the KPL-14 battery are as follows. The gravimetric capacity of the active substance of the pocket oxide-nickel electrode as a hydrogen storage is 22 wt% and the cadmium electrode is 16.9 wt%. The density of the stored energy in the active substance oxide-nickel electrode is 48 kJ/g and in the active substance of the cadmium electrode it is 36.8 kJ/g. The obtained results of the accumulation of hydrogen energy in the electrodes by the electrochemical method are three times higher than any previously obtained results using the traditional thermochemical method.