A numerical model for cylindrical wound lithium-ion cells, which resolves thermal, electrical and electrochemical coupled physics, is presented in this paper. Using the Multi-Scale Multi-Domain ...(MSMD) model framework, the wound potential-pair continuum (WPPC) model is developed as a cell domain submodel to solve heat and electron transfer across the length scale of cell dimension. By defining the cell composite as a wound continuum, the WPPC model can evaluate layer-to-layer differences in electrical potential along current collectors, and electric current in the winding direction to investigate the effects of thermal and electrical configurations of a cell design, such as number and location of tabs, on performance and life of a cylindrical cell. In this study, 20-Ah large-format cylindrical cell simulations are conducted using the WPPC model with the number of electrical tabs as a control parameter to investigate how macroscopic design for electrical current transport affects microscopic electrochemical processes and apparent electrical and thermal output.
•The wound potential-pair continuum (WPPC) model is developed.•It serves a cell-domain model of the Multi-Scale Multi-Domain (MSMD) framework.•It resolves temperature and current collector phase potential variation in cell composites.•It is coupled with submodels solving lithium diffusion dynamics and kinetics.•Electrical/electrochemical/thermal coupled behavior of 20 Ah cylindrical cells was investigated.
The battery technology literature is reviewed, with an emphasis on key elements that limit extreme fast charging. Key gaps in existing elements of the technology are presented as well as ...developmental needs. Among these needs are advanced models and methods to detect and prevent lithium plating; new positive-electrode materials which are less prone to stress-induced failure; better electrode designs to accommodate very rapid diffusion in and out of the electrode; measure temperature distributions during fast charge to enable/validate models; and develop thermal management and pack designs to accommodate the higher operating voltage.
•Key gaps in lithium-based battery technology are presented viz. extremely fast charging.•At cell level, lithium plating on anode remains an issue.•At cell level, stress-induced cracking of cathode material may be an issue.•Safety at pack level must be explored.
Battery thermal barriers are reviewed with regards to extreme fast charging. Present-day thermal management systems for battery electric vehicles are inadequate in limiting the maximum temperature ...rise of the battery during extreme fast charging. If the battery thermal management system is not designed correctly, the temperature of the cells could reach abuse temperatures and potentially send the cells into thermal runaway. Furthermore, the cell and battery interconnect 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 regard 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.
•Aggressive thermal management will be required during extreme fast charging.•Present high energy density cells will need to increase their charge efficiency.•Cell design will have an impact on the temperature variation within the cell.•Battery interconnects will need to be robust and may require a redesign.
► We introduce a fail-safe design for large capacity lithium ion battery systems. ► It facilitates a robust methodology for early stage detection and isolation of a fault. ► Location of faulty cell ...in a module can be identified with the signal measured at module terminals. ► Status of a fault evolution can be determined using the signal form the proposed design.
A fault leading to a thermal runaway in a lithium-ion battery is believed to grow over time from a latent defect. Significant efforts have been made to detect lithium-ion battery safety faults to proactively facilitate actions minimizing subsequent losses. Scaling up a battery greatly changes the thermal and electrical signals of a system developing a defect and its consequent behaviors during fault evolution. In a large-capacity system such as a battery for an electric vehicle, detecting a fault signal and confining the fault locally in the system are extremely challenging. This paper introduces a fail-safe design methodology for large-capacity lithium-ion battery systems. Analysis using an internal short circuit response model for multi-cell packs is presented that demonstrates the viability of the proposed concept for various design parameters and operating conditions. Locating a faulty cell in a multiple-cell module and determining the status of the fault's evolution can be achieved using signals easily measured from the electric terminals of the module. A methodology is introduced for electrical isolation of a faulty cell from the healthy cells in a system to prevent further electrical energy feed into the fault. Experimental demonstration is presented supporting the model results.
The ability to charge battery electric vehicles (BEVs) on a time scale that is on par with the time to fuel an internal combustion engine vehicle (ICEV) would remove a significant barrier to the ...adoption of BEVs. However, for viability, fast charging at this time scale needs to also occur at a price that is acceptable to consumers. Therefore, the cost drivers for both BEV owners and charging station providers are analyzed. In addition, key infrastructure considerations are examined, including grid stability and delivery of power, the design of fast charging stations and the design and use of electric vehicle service equipment. Each of these aspects have technical barriers that need to be addressed, and are directly linked to economic impacts to use and implementation. This discussion focuses on both the economic and infrastructure issues which exist and need to be addressed for the effective implementation of fast charging at 400 kW and above. In so doing, it has been found that there is a distinct need to effectively manage the intermittent, high power demand of fast charging, strategically plan infrastructure corridors, and to further understand the cost of operation of charging infrastructure and BEVs.
•Management of intermittent, high power demand is crucial.•Planning is needed for XFC including siting future corridors.•Planning needs to include cost of charging equipment, operation and installation.•Increased coordination needs to occur between governing authorities.•Safety, cyber physical security, interoperability and compatibility will impact use.
To achieve a successful increase in the plug-in battery electric vehicle (BEV) market, it is anticipated that a significant improvement in battery performance is required to increase the range that ...BEVs can travel and the rate at which they can be recharged. While the range that BEVs can travel on a single recharge is improving, the recharge rate is still much slower than the refueling rate of conventional internal combustion engine vehicles. To achieve comparable recharge times, we explore the vehicle considerations of charge rates of at least 400 kW. Faster recharge is expected to significantly mitigate the perceived deficiencies for long-distance transportation, to provide alternative charging in densely populated areas where overnight charging at home may not be possible, and to reduce range anxiety for travel within a city when unplanned charging may be required. This substantial increase in charging rate is expected to create technical issues in the design of the battery system and the vehicle's electrical architecture that must be resolved. This work focuses on vehicle system design and total recharge time to meet the goals of implementing improved charge rates and the impacts of these expected increases on system voltage and vehicle components.
•BEV refueling time requires 4–6 C-rate charging and large battery capacities.•Peak charge rate less important than average rate for 150–200 mile range recharge.•XFC significantly impacts BEV voltage design, which may impact other EVs.•BEV-charging infrastructure coordination must provide consistent charge experience.
The pursuit of U.S. energy security and independence has taken many different forms throughout the many production and consumption sectors. For consumer transportation, a greater reliance on ...powertrain electrification has gained traction due to the inherent efficiencies of these platforms, particularly through the use of electric motors and batteries. Vehicle electrification can be generalized into three primary categories, hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and battery electric vehicles (BEVs); the latter two, PHEV and BEV, are often referred to as plug-in electric vehicles (PEVs).
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