Explore the vast range of titles available.

Solid‐state lithium batteries may provide increased energy density and improved safety compared with Li‐ion technology. However, in a solid‐state composite cathode, mechanical degradation due to repeated cathode volume changes during cycling may occur, which may be partially mitigated by applying a significant, but often impractical, uniaxial stack pressure. Herein, we compare the behavior of composite electrodes based on Li 4 Ti 5 O 12 (LTO) (negligible volume change) and Nb 2 O 5 (+4% expansion) cycled at different stack pressures. The initial LTO capacity and retention are not affected by pressure but for Nb 2 O 5 , they are significantly lower when a stack pressure of <2 MPa is applied, due to inter‐particle cracking and solid‐solid contact loss because of cyclic volume changes. This work confirms the importance of cathode mechanical stability and the stack pressures for long‐term cyclability for solid‐state batteries. This suggests that low volume‐change cathode materials or a proper buffer layer are required for solid‐state batteries, especially at low stack pressures.

The effects of pressures on electrochemical performance, micro-morphology, surface elemental valence, and cell impedance of nano-silica-based anode all-solid-state lithium batteries (ASLBs) are investigated in this study. The cell under various applied pressures is measured using electrochemical charge/discharge tests, X-ray diffraction (XRD), scanning electron microscopy (SEM), electrochemical impedance test (EIS), and X-ray spectroscopy (XPS). The results indicate that the first cycle lithium insertion capacity reaches its highest value of 3554.5 mAh·g −1 when the Si-based anode undergoes charge and discharge at a rate of 0.1C under a pressure of 100 MPa. Moreover, the coulombic efficiency (CE) at a pressure of 300 MPa reaches a high value of 92.67%, which significantly surpasses the 88.11% under 100 MPa. Meanwhile, higher pressure significantly enhances the cycling performance of Si-based anode, with a capacity of 2268 mAh·g −1 after 100 cycles of charging and discharging at 0.3C under 300 MPa, and a capacity retention rate of 80.21%. SEM images and XPS demonstrated that higher pressures block Si expansion and inhibit crack formation in the Si-based anode, and meanwhile the lower pressure would lead to severe decomposition of Li 6 S 5 Cl in the electrode after long-term cycling and hence resulting in more SEI generation in the Si-based anode. The XPS results demonstrate that. The EIS test results show that the impedance of solid-state batteries is lower under a pressure of 300 MPa, indicating an improved interface of the ASLBs.

A pouch battery pack includes multi-stacked battery module structures that protect the inner pouch battery cells from external hazards and deformation that may arise due to swelling effects. Recent research has found that the stack pressure, which is the suppressing force on the battery cells inside the battery module structure, has a significant impact on the degree to which the state-of-health (SOH) degrades and amount that the mechanical properties of pouch batteries change. Consequently, it is important to optimize the battery module structure design with consideration of the SOH and the structural reliability. To identify how significantly design affect the SOH and the mechanical properties, experiments under different levels of initial stack pressure and uncertainty quantification using Gaussian process are explored in this research. Reliability-based design optimization for the pouch battery module optimize the structural design that minimizes volume while satisfying structural reliability and SOH requirements. This work suggests a data-driven approach for achieving reliability-based design using experiment. Further, this research suggests formulations to calculate the performance functions, which are significant factors for reliable design of pouch battery modules.

Increasing requirements for reducing energy consumption result in window tightness, which decreases the air ventilation rate. This study examines the volume flow rate, stack pressure difference, and pressure losses for a one-person workroom of a semi-detached house under changing window tightness; the determination of the pressure losses and the uncertainty estimation of the examined quantities are described in full detail. The basic indoor air properties of relative humidity and density were determined only by readouts from a gauge and thermodynamic constants. One gauge with a vane probe measured the air velocity and temperature at a grille; a second gauge with an indoor air quality (IAQ) probe measured the mole fraction of carbon dioxide, temperature, absolute pressure, and humidity. The measurements were taken in ten one-week series throughout the year. Stack ventilation performance was good, as the IAQ satisfies the present requirements; however, the uncertainties sometimes exceeded the determined values significantly.

All-solid-state lithium–sulfur batteries (ASSLSBs) represent a crucial frontier in energy storage research, promising higher energy densities and improved safety over traditional lithium-ion systems. Despite their advantages, ASSLSBs face significant challenges, particularly in addressing interfacial instability and mechanical issues arising from the insulating nature and volume expansion of sulfur cathodes. Since the interfaces of all-solid-state batteries cannot accommodate the large volume changes, interfacial contact issues become increasingly pronounced in systems utilizing S8 conversion chemistry. Therefore, applying stack pressure during cell operation is considered a critical factor for optimizing the performance and cycle life of ASSLSB systems. In this study, we systematically investigated the impact of stack pressure on the electrochemical behavior of ASSLSBs under four different stack pressures. Electrochemical cycling results showed a marked difference in capacity retention—74% retention after 100 cycles at high pressure, while only 6% capacity retention was observed at low pressure. This pressure-dependent cycling performance was analyzed from two perspectives: the Li+/e⁻ transport properties and cathode interfacial resistance. Detailed electrochemical characterizations revealed that low stack pressure leads to contact loss and deactivation of active material, which disrupts the effective ion transport pathways and increases interfacial resistance, significantly impairing the overall performance of the cell. This work highlights the critical role of stack pressure in enhancing the electrochemical performance of ASSLSBs, providing key insights for optimizing interfacial stability and transport properties in the field of all-solid-state batteries.

All‐solid‐state batteries (ASSBs) employing sulfide‐based solid electrolytes are attractive energy storage systems because of their potential advantages, such as efficient single‐ion conduction and the absence of electrolyte leakage. Although pellet‐type cells are commonly used in laboratory electrochemical testing under high stack pressure, practical application demands scalable sheet‐type configurations operable under minimal stack pressure. This study demonstrates the feasibility of sheet‐type ASSBs fabricated via slurry casting combined with cold isostatic pressing (CIP) for operation under minimal stack pressure. CIP process allows uniform densification and intimate interparticle contact, resulting in the formation of continuous lithium‐/electron‐conducting pathways within the composite electrode. In addition to the processing pressure, the composite electrode formulation with a dimensionally invariable positive electrode material, Li8/7Ti2/7V4/7O2, is systematically optimized by tuning the conductive additive content to balance ionic and electronic conduction pathways, which is a critical factor for maximizing electrochemical performance. Furthermore, the optimized composite electrodes with Li8/7Ti2/7V4/7O2 show stable long‐term cycling under minimal stack pressure (<0.5 MPa). These findings demonstrate that rational microstructural design for composite electrodes through scalable processing enables high‐performance sheet‐type ASSBs with strong practical viability. This study demonstrates the feasibility of sheet‐type ASSBs fabricated via slurry casting combined with cold isostatic pressing for operation under minimal stack pressure (< 0.5 MPa). Uniform densification and optimized composite electrode formulation with Li8/7Ti2/7V4/7O2 enable continuous lithium‐/electron‐conducting pathways and stable long‐term cycling.

As solid‐state batteries (SSBs) with lithium (Li) metal anodes gain increasing traction as promising next‐generation energy storage systems, a fundamental understanding of coupled electro‐chemo‐mechanical interactions is essential to design stable solid‐solid interfaces. Notably, uneven electrodeposition at the Li metal/solid electrolyte (SE) interface arising from intrinsic electrochemical and mechanical heterogeneities remains a significant challenge. In this work, the thermodynamic origins of mechanics‐coupled reaction kinetics at the Li/SE interface are investigated and its implications on electrodeposition stability are unveiled. It is established that the mechanics‐driven energetic contribution to the free energy landscape of the Li deposition/dissolution redox reaction has a critical influence on the interface stability. The study presents the competing effects of mechanical and electrical overpotential on the reaction distribution, and demarcates the regimes under which stress interactions can be tailored to enable stable electrodeposition. It is revealed that different degrees of mechanics contribution to the forward (dissolution) and backward (deposition) reaction rates result in widely varying stability regimes, and the mechanics‐coupled kinetics scenario exhibited by the Li/SE interface is shown to depend strongly on the thermodynamic and mechanical properties of the SE. This work highlights the importance of discerning the underpinning nature of electro‐chemo‐mechanical coupling toward achieving stable solid/solid interfaces in SSBs. This work explores the thermodynamic foundations of mechanics‐coupled reaction kinetics and reveals its implications on electrodeposition stability in solid‐state batteries. Depending on the material properties of the solid electrolyte (SE), lithium (Li) metal/SE interfaces can exhibit distinct mechanics‐driven energetic contributions to the free energy landscape of the reaction, resulting in different scenarios of mechanics‐reaction kinetics coupling and electrodeposition stability regimes.

Stack pressure and temperature serve as effective means to induce deformation of the lithium metal anode toward the Li/solid‐state‐electrolyte interface, thereby mitigating the well‐known issue of void formation during high‐current‐density stripping. In this study, a compelling methodology is systematically assessed for determining the critical stack pressure and temperature of Li metal anode in conjunction with Li7La3Zr2O12 (LLZO) solid‐state electrolyte, which is the minimum set of values required to maintain conformal contact between Li and LLZO at a given current density. The methodology is based on the analysis of the second derivatives of the voltage profiles of identical Li/LLZO/Li symmetric cells measured during one half‐cycle (3 mAh cm‐2) at the same current density but different stack pressures. The effectiveness of the presented approach in assessing conditions for mitigating void formation during Li stripping is evaluated through cycle stability tests performed on Li/LLZO/Li symmetric cells. This study delves into the influence of stack pressure and temperature on the deformation of lithium metal anodes toward the Li/LLZO interface, aiming to minimize void formation at the Li/LLZO interface when subjected to high‐current‐density Li stripping. A methodology presented allows the evaluation of critical conditions for maintaining conformal contact between lithium metal anode and the LLZO solid‐state electrolyte.

Determining the optimal ceramic content of the ceramics-in-polymer composite electrolytes and the appropriate stack pressure can effectively improve the interfacial contact of solid-state batteries (SSBs). Based on the contact mechanics model and constructed by the conjugate gradient method, continuous convolution, and fast Fourier transform, this paper analyzes and compares the interfacial contact responses involving the polymers commonly used in SSBs, which provides the original training data for machine learning. A support vector regression model is established to predict the relationship between the content of ceramics and the interfacial resistance. The Bayesian optimization and K-fold cross-validation are introduced to find the optimal combination of hyperparameters, which accelerates the training process and improves the model’s accuracy. We found the relationship between the content of ceramics, the stack pressure, and the interfacial resistance. The results can be taken as a reference for the design of the low-resistance composite electrolytes for solid-state batteries.

Stack pressure is broadly explored in improving contact at the lithium metal–solid‐state electrolyte interface of all‐solid‐state lithium‐metal batteries (ASSLBs). The effectiveness of this procedure relies heavily on the time‐dependent accommodation of lithium sheets under confined conditions. Herein, a continuum modeling framework coupling power‐law creep and diffusion is developed to investigate the mechanical behavior of pressed lithium layers of different thickness. It is revealed that lateral shear stress arising from interfacial confinement retards plastic accommodation in lithium layers. This detrimental effect becomes increasingly significant as lithium layers’ thickness H decreases or their diameter D to thickness H ratio (D/H) increases. For layers of higher D/H, the stack pressure to realize a constant strain rate is proportional to (D/H)(1 + m)/m, where m is the power‐law creep exponent. Diffusion is beneficial to lithium deformability through reducing interfacial shear stresses and boosting power‐law creep at constant stack pressure. A critical thickness characterizing the dominance of diffusion over creep is theoretically determined and validated through modeling for a wide range of deformation rates. Collectively, these findings advance the fundamental understanding of confined lithium mechanics and provide quantitative guidelines for the structural design and pressure management of ASSLBs. Plastic accommodation of lithium metal under stack pressure is essential for maintaining Li/SSE interfacial contact. Through continuum modeling, it is revealed that interfacial confinement induces lateral shear stresses and impedes plastic flow. Diffusion mitigates these stresses, enhancing deformability and power‐law creep. A derived critical thickness marks the transition from power‐law creep to diffusion‐dominated behavior, informing ASSLB design.