1. “A Polymer-Binder-Free Approach to Creating Functional LiFePO₄ Cathodes by Organic Ionic Plastic Crystal-Derived Ion-Conductive Binders”
by Daniela M. Josepetti, Maria Forsyth, Patrick C. Howlett and Hiroyuki Ueda
Batteries 2025, 11(1), 3; https://doi.org/10.3390/batteries11010003
Available online: https://www.mdpi.com/2313-0105/11/1/3
Cover Story: Overcoming the performance limitations of lithium-ion batteries requires innovative strategies, such as replacing non-conductive electrode components with conductive alternatives. This study pioneers the elimination of non-conductive polymer binders from LiFePO₄ cathodes and explores binary mixtures of an organic ionic plastic crystal (OIPC) and lithium salt as both binders and pre-filled electrolytes in the electrode layer. By varying the electrode composition, this polymer-binder-free strategy enables the formulation of two types of LiFePO₄ cathodes: thick electrodes with high areal capacity (expected ≤3.74 mAh/cm²) and thin ones with superior rate capability. This work demonstrates the OIPC’s innovative functionalities for battery applications and discusses the potential integration of the cathodes into solid-state batteries. 

2. “Lithium Tracer Diffusion in LixCoO₂ and LixNi1/3Mn1/3Co1/3O₂ (x = 1, 0.9, 0.65)-Sintered Bulk Cathode Materials for Lithium-Ion Batteries”
by Erwin Hüger, Daniel Uxa and Harald Schmidt
Batteries 2025, 11(2), 40; https://doi.org/10.3390/batteries11020040
Available online: https://www.mdpi.com/2313-0105/11/2/40
Cover Story: Knowledge of Li diffusivities in electrode materials of Li-ion batteries is essential for the fundamental understanding of charging/discharging times, maximum capacities, stress formation and possible side reactions. The present work investigates the difference in diffusion between Li-deficient Li_xNi_1/3Mn_1/3Co_1/3O₂ and Li_xCoO₂ cathode materials prepared by solid-state reaction and electrochemical delithiation. Electrochemical delithiation produces a vacancy-rich state suitable for fast Li diffusion. This is not the case for samples prepared by solid-state reaction. Consequently, the design and use of a cathode initially made from a Li-deficient material does not improve the kinetics of battery performance.

3. “Air-Outlet and Step-Number Effects on a Step-like Plenum Battery’s Thermal Management System”
by Olanrewaju M. Oyewola, Emmanuel T. Idowu, Morakinyo J. Labiran, Michael C. Hatfield and Mebougna L. Drabo      
Batteries 2025, 11(3), 87; https://doi.org/10.3390/batteries11030087
Available online: https://www.mdpi.com/2313-0105/11/3/87
Cover Story: The Z-type BTMS’s structure is one of the most widely investigated air-cooled TMSs. Several designs of air-cooled BTMSs are often associated with the drawback of a rise in ΔP, consequently resulting in an increase in pumping costs. In this study, the investigation of a Step-like plenum design was extended by exploring one and two outlets to determine possible decreases in the maximum battery temperature (Tmax), maximum battery temperature difference (ΔTmax), and pressure drop (ΔP). The computational fluid dynamics (CFD) method was employed to predict the performances of different designs. The designs combine Step-like plenum and two outlets with the outlets located at different points on the BTMS. The results from the study revealed that using a one-outlet design, combined with a Step-like plenum design, reduced the Tmax by 3.52 K when compared with that of the original Z-type system.

4. “Ion and Water Transports in Double Gyroid Nanochannels Formed by Block Copolymer Anion Exchange Membranes”
by Karim Aissou, Maximilien Coronas, Jason Richard, Erwan Ponsin, Sambhav Vishwakarma, Eddy Petit, Bertrand Rebiere, Camille Bakkali-Hassani, Stéphanie Roualdes and Damien Quemener
Batteries 2025, 11(4), 126; https://doi.org/10.3390/batteries11040126
Available online: https://www.mdpi.com/2313-0105/11/4/126
Cover Story: K. Aissou et al. report the fabrication of polymeric membranes with optimized ionic conductivity (IC) and good permeability—key properties for next-generation anion exchange membranes (AEMs) aimed at reducing Ohmic losses and improving water management in alkaline membrane fuel cells. Hydrophilic ion-conducting double-gyroid (DG) nanochannels were created within block copolymer (BCP) AEMs by combining solvent vapor annealing (SVA) with a methylation process. The resulting DG-structured BCP AEMs, in their OH⁻ counter-anion form, exhibited an IC of ~2.8 mS.cm⁻¹ at 20 °C and high water permeability (~384 LMH.bar⁻¹), whereas as-cast AEM analogs with a disordered phase showed much lower IC values (~1.2 mS.cm⁻¹).

5. “A Review of Battery Energy Storage Optimization in the Built Environment”
by Simone Coccato, Khadija Barhmi, Ioannis Lampropoulos, Sara Golroodbari and Wilfried van Sark
Batteries 2025, 11(5), 179; https://doi.org/10.3390/batteries11050179
Available online: https://www.mdpi.com/2313-0105/11/5/179
Cover Story: Battery energy storage systems (BESSs) are becoming essential in the built environment, supporting self-consumption, peak shaving, grid support, and market participation at both local and national levels. This review offers a systematic overview of current applications and optimization techniques, including battery degradation modeling and multi-objective control strategies. By focusing on real-world challenges in residential and urban contexts, it highlights where technical potential remains underutilized and outlines directions for future research that bridge theory and implementation.

6. “Detailed Characterization of Thermal Runaway Particle Emissions from a Prismatic NMC622 Lithium-Ion Battery”
by Felix Elsner, Peter Gerhards, Gaël Berrier, Rémi Vincent, Sébastien Dubourg and Stefan Pischinger
Batteries 2025, 11(6), 225; https://doi.org/10.3390/batteries11060225
Available online: https://www.mdpi.com/2313-0105/11/6/225
Cover Story: Particles ejected during the thermal runaway (TR) of lithium-ion batteries can cause damage to other components in the battery system. The associated safety hazards should therefore be addressed in the battery pack development process. To gain a detailed understanding of the TR particle characteristics, several analyses are carried out. For detailed size and shape quantification, dynamic image analysis and large-particle image processing are applied for the first time. TR particles cover a wide size range, from micrometers to centimeters, and are clearly non-spherical. The analysis indicates particle temperatures of ~200–1100 °C at the time of cell ejection. Particles are partially combustible, and the reactivity is non-linearly size-dependent. Several implications for battery system development are outlined.

7. “Impact of Temperature and Depth of Discharge on Commercial Nickel Manganese Oxide and Lithium Iron Phosphate Batteries After Three Years of Aging”  
by Matthieu Dubarry, Andrew Pearson, Keiran Pringle, Youssof Shekibi and Steven Pas
Batteries 2025, 11(7), 239; https://doi.org/10.3390/batteries11070239
Available online: https://www.mdpi.com/2313-0105/11/7/239
Cover Story: Accurate cell selection is paramount to ensure battery safety and longevity. Unfortunately, due to path dependence, determining which cells are best adapted to a specific application is not straightforward and might require significant testing. This work provides the analysis of three years of aging, for both cycling and calendar years, for two batches of commercial cells of different chemistries. Using the design of experiments and analysis of variance, this work showed that the impact of temperature and the depth of discharge, both at the beginning and end of the discharge, are chemistry-dependent. Moreover, an analysis of the cells’ degradation modes also showcased different pathways depending on the positive electrode chemistry and the type of aging.

8. “Influence of Pulse Duration on Cutting-Edge Quality and Electrochemical Performance of Lithium Metal Anodes”
by Lars O. Schmidt, Houssin Wehbe, Sven Hartwig and Maja W. Kandula
Batteries 2025, 11(8), 286; https://doi.org/10.3390/batteries11080286  
Available online: https://www.mdpi.com/2313-0105/11/8/286
Cover Story: Lithium metal is a promising anode for next-generation batteries, but its processing is challenging due to high reactivity and poor machinability. This study investigates laser cutting as a non-contact alternative to mechanical separation, comparing nanosecond and picosecond pulse durations. Analysis of cutting-edge quality, heat-affected zones, and melt formation shows that shorter pulses reduce thermal damage and improve electrode integrity. Electrochemical tests in symmetric Li|Li cells reveal that laser-cut anodes outperform mechanically separated ones, exhibiting improved cycling stability despite locally inactive lithium. These results highlight optimized laser processing as a key step toward reliable lithium metal anodes for solid-state batteries.

9. “Effect of Short-Chain Polymer Binders on the Mechanical and Electrochemical Performance of Silicon Anodes”
by Fei Sun, L. Zurita-Garcia and Dean R. Wheeler
Batteries 2025, 11(9), 329; https://doi.org/10.3390/batteries11090329  
Available online: https://www.mdpi.com/2313-0105/11/9/329
Cover Story: In their pristine state, silicon particles, carbon black, and binders form a compact and well-adhered network on the copper current collector with about 40% porosity. Upon lithiation, however, silicon expands nearly 300%, forcing the composite to rearrange and partially detach from the collector. This expansion leads to cracks and delamination, weakening the electrode’s integrity. The binders used to make composites in this study are intended to accommodate these structural changes, highlighting the urgent need for binder designs that can withstand silicon’s immense volume fluctuations.

10. “Hollow Carbon Nanorod-Encapsulated Eu₂O₃ for High-Energy Hybrid Supercapacitors”             
by Arslan Umer, Daniel W. Tague, Muhammad Abbas, John P. Ferraris and Kenneth J. Balkus, Jr.
Batteries 2025, 11(10), 355; https://doi.org/10.3390/batteries11100355
Available online: https://www.mdpi.com/2313-0105/11/10/355
Cover Story: Hollow carbon nanorods encapsulating europium oxide (Eu₂O₃) offer a unique way to combine electric double-layer capacitance (EDLC) and pseudocapacitance (PC) in a single material. The carbon framework ensures high conductivity and a large surface area, while the Eu₂O₃ provides active redox sites for high energy density. This strong carbon and Eu₂O₃ interface enables efficient charge transfer, resulting in a high energy hybrid supercapacitor. Moreover, the Eu₂O₃ can also be recovered and reused, making the process efficient and sustainable.

11. “Techno-Economic and Environmental Viability of Second-Life EV Batteries in Commercial Buildings: An Analysis Using Real-World Data”   
by Zhi Cao, Naser Vosoughi Kurdkandi and Chris Mi
Batteries 2025, 11(11), 412; https://doi.org/10.3390/batteries11110412
Available online: https://www.mdpi.com/2313-0105/11/11/412
Cover Story: Second-life electric vehicle batteries retain substantial usable capacity after automotive retirement, offering a cost-effective and low-carbon solution for stationary storage. This study evaluates a second-life battery energy storage system in a California commercial building using one year of real-world operational data. By comparing second-life and new battery systems under identical dispatch, load, and tariff conditions, the analysis quantifies their economic and environmental performance. The results show that second-life batteries achieve higher economic returns and lower carbon intensity than new batteries despite their lower efficiency. The findings confirm that acquisition cost and policy incentives are the primary drivers of economic viability, while environmental benefits depend mainly on grid carbon intensity.

12. “NiCo₂O₄ Electrodes Prepared by Inkjet Printing on Kapton Substrates for Flexible Supercapacitor Applications”
by Angeliki Banti, Paris Pardalis, Eleni Mantsiou, Michalis Charalampakis, Vassilios Binas, Andronikos C. Balaskas and Sotirios Sotiropoulos
Batteries 2025, 11(12), 434; https://doi.org/10.3390/batteries11120434
Available online: https://www.mdpi.com/2313-0105/11/12/434
Cover Story: This work presents a flexible NiCo₂O₄ electrode produced through low-temperature inkjet printing on Kapton substrates designed for next-generation wearable electronics. The printed oxide shows strong pseudocapacitive performance under bending. The scalable fabrication approach supports lightweight, conformable energy storage components that can be seamlessly integrated into wearable and body-mounted devices.