Insights on the Fast Charging of Lithium-ion Batteries, Daniel Abraham
Fast charging of lithium-ion batteries, being developed for electric vehicles, is needed to meet customer demands of time-parity with today’s gasoline-powered cars. This presentation is an overview of extreme fast charge studies being conducted at Argonne National Laboratory. Methodologies to monitor electrode polarization, detect Li-plating, examine lithium concentration gradients in electrodes and investigate electrode materials changes, during and after exposure to high currents, will be discussed.
Oxide Anode Materials for Fast-Charge Li-ion Batteries, Jan Allen
Oxide anode materials are of high interest for the development of fast charge Li-ion batteries. Oxide materials offer the advantage of a higher lithium intercalation potential of ~ 1.5-1.6 V versus Li / Li+ relative to graphite which reduces the likelihood of Li plating during fast Li-insertion. Furthermore, the high gravimetric density and multi-electron transfer per transition metal offers the potential for high volumetric energy density on par with graphitic anodes. This talk will cover ARL efforts towards the development of new oxide anode materials to potentially replace the existing, commercialized Li4Ti5O12 oxide anode.
100% Silicon anodes for achieving both higher cell energy density and 600 15-minute fast charging cycles, Rob Anstey
Li-ion cells incur a trade-off between power and energy. Lithium metal anodes are energy dense. However, absent a host structure or external compression and heat, high charge rates can induce plating that impedes performance. We overcome the adverse effect through a novel 100% silicon anode having an adhesion layer that chemically and electronically bonds the silicon to an engineered copper foil. This enables higher energy densities and mitigates expansion forces. This technology enables over 600 cycles of 15-minute charging, while increasing cell energy density by >30% relative to comparable graphite cells. This could enable EVs with over 450 miles of range and the ability to charge 250 miles in 15 minutes, for over 150,000 miles of fast charging lifetime. The technology may be applicable to EVTOL and military applications requiring high power and energy densities. The supply chain depends on US feedstocks and European equipment.
EV charging in 5-15 minutes. A review of the ARPA-E, EVs4ALL program, Halle Cheesman
Key to the success of Electric Vehicles are reliable, inexpensive batteries that can charge fast and provide improved performance and range retention in cold weather compared to state-of-the-art commercial options. ARPA-E's EVs4ALL program will increase EV market share by developing next-generation battery technologies to significantly improve EV affordability, convenience, reliability, and safety. One contributor among others to success is the ability to restore 80% of cell capacity in less than 15 minutes.
Extreme fast charging: Identification of failure modes and routes to improve performance, Eric Dufek
Range anxiety is seen as a key limitation by many consumers looking to purchase an electric vehicle. The two routes to alleviate this anxiety are through the development of higher energy batteries and batteries capable of charging in 10 minutes or less. Achieving either target is difficult and presents a suite of challenges spanning from material degradation through cell and electrode design. When performing extreme fast charging, many types of degradation emerge including Li deposition and cathode cracking. Early detection and understanding using electrochemical methods are complicated, but possible if using a multitude of different signatures. Here we describe recent efforts to jointly align electrochemical methods with targeted characterization and advanced analysis to detect failure modes. Specifically, machine learning and other advanced analysis approaches show promise to reduce the time and effort needed to predict life, delineate failure modes, and provide input to electrochemical models. Here we discuss the use of machine learning to perform early failure mode classification on cells used for fast charge applications. Using this information, it is then possible to feedback information for the refinement of advanced charging protocols designed to minimize specific aging pathways.
Battery Thermal Implications Associated with Extreme Fast Charging, Matt Keyser
Present-day thermal management systems for battery electric vehicles are inadequate in limiting the maximum temperature rise of the battery during extreme fast charging. Incorrect thermal management designs for extreme fast charging conditions could result in cells reaching abuse temperatures and potentially sending the cells into thermal runaway. Furthermore, the cell and module design needs to be improved to meet the lifetime expectations of the consumer. Each of these aspects is explored and addressed as well as outlining where the heat is generated in a cell, the efficiencies of power and energy cells, and what type of battery thermal management solutions are available in today’s market. Thermal management is not a limiting condition with regards to extreme fast charging, but many factors need to be addressed especially for future high specific energy density cells to meet U.S. Department of Energy cost and volume goals.
Automotive Perspectives on EV Battery Fast Charging Enabling Technologies, Brian Robert
With aggressive battery charging for vehicles comes concerns of reduced life and temperature stability. Enabling technologies, such as advanced thermal management and high voltage architectures, aid the charging gap and customer range anxiety. However, as automotive OEMs target increasing electrified vehicle range and decreasing charge time, trade-offs in system design – also considering the potential in emerging solid state cells – create new opportunities and challenges.
Enabling High-Rate Lithium Metal Anodes by Tailored Structures and Interfaces, Eric Wachsman
Oxide-based solid-state Li-batteries (SSLiBs) have the potential to be a transformational and intrinsically safe energy storage solution due to their non-flammable ceramic electrolyte that enables the use of high-capacity Li metal anodes and high voltage cathodes for higher energy density over a much wider operating temperature range. However, their progress has been limited due to electrode/electrolyte interfacial issues. In particular for Li-metal anodes concerns over dendrite formation/propagation and the requirement for elevated temperature and high stack pressure are still prevalent. To eliminate these concerns a rational design of tailored structures and interfaces in Li-metal anodes will be presented. In addition, progress toward full cells using these tailored structures and interfaces will be presented.
Smaller, Faster-Charging Batteries for Affordable and Sustainable Electric Vehicles, Chao-Yang Wang
An asymmetric temperature modulation (ATM) approach to enabling 10-minute fast charging of energy-dense Li-ion batteries in any temperatures (even at -50°C) while still delivering remarkable cycle life will be presented. We further show that smaller, faster-charging batteries are the answer to affordable and sustainable electric vehicles for everyone, everywhere, especially in the era of critical materials and battery shortages. Finally, we discuss a figure of merit for fast charging batteries composed of three metrics simultaneously: charge time (<10 min), specific energy acquired by fast charge (>200 Wh/kg), and cycle number (>1000) under the fast charge condition.
A Guide to Use LiFSI in Fast-charging Electrolytes of Li-ion Batteries, Sheng S. Zhang
Lithium bis(fluorosulfonyl)imide (LiFSI) is a magic salt, however, the controversy about the anodic corrosion of aluminum (Al) cathode current collector in its solutions has long remained among the battery community. This presentation aims to clarify the mystery of Al corrosion in LiFSI electrolytes and discuss the suitability of LiFSI as a single salt in low-to-moderate concentration (<2.0 M) electrolytes for high-voltage Li metal and Li-ion batteries. Importantly, it is found that there is a solvent-related “threshold potential”, above which Al is subject to uncontrollable corrosion. In coin cells, LiFSI electrolytes are much more corrosive to stainless steel (SS) spacer than the Al current collector. Most of the previous controversies and failures in the coin cell tests can be attributed to the corrosion of the SS spacer, other than the corrosion of the Al current collector. We concluded that LiFSI electrolytes are suitable for high-voltage batteries as long as at the cathode, the charging voltage is limited to the “threshold potential” and the SS components are avoided. This conclusion is verified by the successful operation of the Li-ion pouch cells where the SS components are absent at the cathode.