Dear Colleagues,

Compared to traditional combustion-engine-powered vehicles that can be refilled in 5 min, electric vehicles, especially those with high energy-density batteries, currently take much longer to refill. To meet the expectations of consumers, fast-charging lithium batteries are desirable and considered a key challenge for the widespread adoption of electric vehicles. Many obstacles such as extensive energy decay and safety issues hinder the fast-charging target of charging to 80% state of charge within 10‒15 min. Recently, the fast-charging-related research has increased rapidly, and more research is expected in coming years. This Special Issue is looking for contributions to help us understand the mechanism and obstacles of fast charging and gather innovative studies on novel materials and technologies to improve fast-charging capability of batteries.

Potential topics include but not are limited to:

• Li-ion batteries, Li metal batteries, Li-S, Li-O, etc.
• Material development including anode, cathode, electrolyte, etc.
• Electrode and cell design and fabrication.
• Cell performance testing including cycle life and thermal safety investigation.
• Characterization methodology investigation.
• Modeling and machine learning to understand and predict cell performance.

Dr. Mei Luo
Dr. Wenquan Lu
Guest Editors

Manuscript Submission Information

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Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Batteries is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2700 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

• lithium ion batteries
• lithium batteries
• fast charging
• lithium plating
• cycle life
• electrode architecture
• modeling and machine learning
• thermal safety

Title: Enhancing Lithium-Ion Battery Rate Capabilities with High Aspect Ratio Conductive Additives
Authors: Olivier Kasikala 1,2; Wenquan Lu 3; Bernard Bladergroen 2; Oluwaseun Oyekola 1
Affiliation: 1. Cape Peninsula University of Technology, South Africa; 2. University of the Western Cape, South Africa; 3. Argonne National Laboratory, USA.
Abstract: Achieving higher rate capabilities in lithium-ion batteries (LIBs) is crucial to meet the surging demand of modern energy storage applications. This improvement hinges on enhancing both electron and ion transport within the battery's electrodes. To enhance electron transport, long-range electrical connections must be fostered, short-range contacts must be created, and robust cohesion and adhesion must be established within the microstructure of the electrode. Similarly, optimizing the electrode's porosity and tortuosity is key to achieving efficient ion transport. The research presented in this paper explores innovative conductive additives, specifically multi-walled carbon nanotubes (MWCNTs) and graphene nanoribbons (GNRs), that are integrated into the electrode slurry to focus on these critical aspects. The study evaluates various mixing sequences and conditions to determine their impact on the slurry's rheological properties and the uniform distribution of these conductive additives within the carbon-binder matrix. Through a combination of Through-Plane Conductivity (TPC) and Scanning Electron Microscopy (SEM) analyses, the research establishes the minimal yet effective ratio of conductive additives necessary to achieve an ideal percolation threshold for electrical connectivity. The findings indicate that using HARCA instead of CB leads to a 63% decrease in conductive additive content, resulting in improved battery performance and a 4% increase in energy density. The study also reveals that CNTs and GNRs have the potential to enhance electron and ion transport, as well as offer a more stable and processable slurry composition. By comparing these HARCA-based electrodes with traditional carbon black-based ones, the research highlights the promising role of CNTs and GNRs in enhancing the rate capabilities of LIBs, thereby paving the way for more efficient and robust batteries in the future.

Title: The Response fast charging of 18650 lithium ion batteries at different C-rates and temperatures
Authors: Filip Leemans; Grietus Mulder; Carlo Mol; Mmalewane Modibedi; Enose Moholisa; Thabang Reuben Mabeo; Renesh Thakoordeen; Rigardt Coetzee
Affiliation: 1. Flemish institute for technological research, Belgium; 2. Council of Scientific & Industrial Research, South Africa
Abstract: As the demand for electric vehicles rises, efficient and rapid-charging lithium-ion batteries become increasingly imperative. This study explores tests to understand the performance of 18650 Li-ion cells under fast-charging conditions. Experimental studies cover dynamic stress testing, voltage and current profile analysis, partial state of charge cycling, temperature ramp-up testing, and charge/discharge efficiency testing. Dynamic stress testing evaluates cells' response to rapid charging and discharging, simulating challenging conditions. Voltage and current profile analysis examines dynamic behaviour during fast-charging cycles, elucidating patterns impacting performance. Partial state of charge cycling mimics real-world fast-charging, assessing cells' response to irregular charging. Temperature ramp-up testing studies thermal response during rapid charging, exploring temperature effects on cycle life and capacity. Cycling at low temperatures assesses cells' performance in challenging environments, studying effects on fast-charging efficiency. Charge/discharge efficiency testing quantifies the efficiency of fast-charging by evaluating charged capacity to energy supplied. The test will also include high temperature study of 50°C to simulate the higher temperatures South Africa can experience due to climate change. These tests deepen understanding of obstacles and mechanisms in fast-charging lithium-ion batteries. Findings offer insights how charge and discharge rates at different-rates and temperatures affect the overall energy retention, state of health, and lifespan or cycle of technologies, and testing protocols, aiming to overcome challenges and facilitate electric vehicle adoption.

Title: Unveiling SOC-DOD Synergies in High-Rate Cycling of LiFePO4/Graphite Cells
Authors: Vallabha Rao Rikka 1,2,*; Abhijit Chatterjee 2; G Sundararajan 1; R Gopalan 1; Raju Prakash 1
Affiliation: 1. Centre for Automotive Energy Materials, International Advanced Research Centre for Powder Metallurgy and New Materials (ARCI), Chennai, 600113, Tamil Nadu, India; 2. Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai 400076, Maharashtra, India
Abstract: 1