Ultrafast Charging Research Articles

External Liquid Cooling Method for Lithium-Ion Battery Modules Under Ultra-Fast Charging

Electric vehicles (EVs) are booming all over the world for a low carbon emission and greener environment. The fast charging is an urgent demand for consumers. However, the dramatic temperature rising during high-power charging has a high risk of trigging thermal runaway and other safety issues. This article proposes an external liquid cooling method for lithium-ion battery module with cooling plates and circulating cool equipment. A comprehensive experiment study is carried out on a battery module with up to 4C fast charging, the results show that the three-side cooling plates layout with low coolant temperature provides better temperature control effect, while the coolant velocity and type have very weak impact. Then the simulation model with high precision is built for ultra-fast charging, and a safe charging range under 5C charging is proposed. The safe charging range under 5C can be increased by 50.1%. The environment close to the room temperature demonstrates the best effects of external cooling. For actual applications in the EVs, the circulating cooling equipment outside EVs can be integrated with high-power charging infrastructure and provide a 117 km improvement in mileage under 5C safe charging which indicates a tremendous application prospect.

Enhanced Electrochemical Performance of Sn(SnO2)/TiO2(B) Nanocomposite Anode Materials with Ultrafast Charging and Stable Cycling for High-Performance Lithium-Ion Batteries

Enhanced Electrochemical Performance of Sn(SnO₂)/TiO₂(B) Nanocomposite Anode Materials with Ultrafast Charging and Stable Cycling for High-Performance Lithium-Ion Batteries

Mechanisms of Lithium-Ion Transport in Solid-State Electrolyte and Cathode Materials Prepared By PVD

Conventional liquid-state lithium-ion batteries are currently limited in their energy density, lifetime, thermal stability, and safety. The design of viable solid-state batteries shows promise to improve upon the shortcomings of liquid cells. Removal of organic electrolytes increases the lifetime while making these batteries more environmentally friendly and safe. Solid-state batteries also have the potential to demonstrate higher energy density and provide ultrafast charging. However, these desirable properties require significant efforts to uncover and utilize the chemical, morphological, and electrochemical properties of solid-state electrolytes and cathode nanocomposites. This study addresses physical vapor deposition (PVD) technology for design of solid-state material architectures with the properties needed to create high-performance electrochemical cells. The PVD process allows cathodes and electrolytes to be deposited as dense films, thereby increasing their energy density and electrochemical performance. Furthermore, this process results in excellent adhesion between dissimilar materials allowing for increased electrical and ionic conductivity. This work uses lithium oxyhalide electrolytes and eco-friendly lithium iron phosphate cathodes, which were both deposited in vacuum using radio frequency power and magnetron sputtering sources. A co-deposition technique was used to successfully deposit thin film layers of cathode, electrolyte, cathode/electrolyte mixture, and carbon thin films in a single process. Electrochemical cells with different functional layers deposited by PVD (~7 mm) were compared to the cells with commercial LFP cathodes (~32 mm thick). The electrochemical cells created by PVD showed lower charge transfer resistances and high electrochemical stability at ultra-high (10C) charging rates. Significant improvements in performance are expected to continue as the process is improved in terms of ionic and electronic transport at cathode-electrolyte interfaces. The authors acknowledge financial support from the DOD Navy SBIR Phase II project (N68335-18-C-0021), the NSF IUCRC program for supporting the “Center for solid-state electric power storage” (#2052631), and the South Dakota “Governor’s Research Center for electrochemical energy storage”. Figure 1

Cell selection and thermal management system design for a 5C-rate ultrafast charging battery module

In the pursuit of ultrafast charging electric vehicles, cell selection and thermal management play a critical role. This work explores the selection of a suitable battery cell, design of a battery module thermal management system, and thermal modelling of the cells and module. Four different cells are compared, each with unique characteristics that present advantages and disadvantages for ultrafast charging. The cells are first characterized in a lab, and their suitability for ultrafast charging is evaluated based on the experimental results. Factors such as charging efficiency and required cooling system size are also considered. Simplified thermal models are used for comparison of the different cells. A three-cell, liquid-cooled test module is designed and constructed for a selected cell, and detailed fluid and thermal models are developed for the module. Module temperatures at steady state and over time—during a series of fast charges and over a repeated driving and fast charge cycle—are simulated and compared to lab measurements. For a 5C charge, a peak temperature of 34.6°C is measured in the lab, and modelled within 0.6°C.

Water-based Cooling Fluids to Mitigate the Thermal Management Challenges in New Energy Vehicles

Thermal management is considered one of the key enablers for the adoption of New Energy Vehicles. An efficient design of an electrified vehicle’s cooling system, be it a HEV, BEV or FCEV, is of major importance to guarantee vehicle lifetime, optimize energy efficiency, enable adequate driving range and allowing high charging speed. Moreover, it is of critical importance for safety. Compared to internal combustion engine (ICE) vehicles, cooling systems for electrified vehicles have become more complex with increasing integration of a variety of parts. The cooling medium’s main function is no longer limited to cooling of the ICE; it also used to conserve and transport heat to essential powertrain parts such as the battery pack, all while electrical safety cannot be jeopardized. Many recently launched electrified vehicles successfully employ the same water-glycol based cooling liquids that are found in ICE vehicles. In light of future developments such as ultra-fast charging, advances in cooling systems and the cooling liquid are required. Recently, a clear shift from air cooling towards waterbased cooling fluids is witnessed mainly due to the strong beneficial heat transfer properties of water. For direct cooling of fuel cell stacks different changes are demanded since the upper electrical conductivity limit of the aqueous liquid compels the use of new additive technology.

Analysis, Limitations, and Opportunities of Modular Multilevel Converter-Based Architectures in Fast Charging Stations Infrastructures

As fast and ultrafast charging stations (FCS/UFCS) increase their degree of penetration in the grid, it becomes beneficial to connect them directly at the medium-voltage (MV) level, as this reduces volume, losses, and cost. Recent solutions propose the replacement of the typical combination of the low-frequency transformer plus low-voltage rectifier by a solid-state transformer (SST), which can be composed, among other topologies, by a modular multilevel converter. This article proposes and discusses the application of the modular multilevel converter (MMC) in FCS infrastructures, utilized as an active front-end rectifier, either as part of an SST or for direct connection to the second stage, comprised of isolated dc/dc converters. Focus is given on the advantages and limitations of the converter operating as a step-down rectifier, where <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$U_\text{DC}&lt; \hat{U}_\text{AC}$</tex-math></inline-formula> . As different architectures are presented, first the MMC step-down constraints and optimum operation points are explored and discussed, then the architectures are evaluated in terms of key performance indicators, such as size, efficiency, and reliability. At the end, experimental results for a full-scale MV MMC are presented, validating the analysis carried throughout this article.

Review of Solid-State Transformer Applications on Electric Vehicle DC Ultra-Fast Charging Station

The emergence of DC fast chargers for electric vehicle batteries (EVBs) has prompted the design of ad-hoc microgrids (MGs), in which the use of a solid-state transformer (SST) instead of a low-frequency service transformer can increase the efficiency and reduce the volume and weight of the MG electrical architecture. Mimicking a conventional gasoline station in terms of service duration and service simultaneity to several customers has led to the notion of ultra-fast chargers, in which the charging time is less than 10 min and the MG power is higher than 350 kW. This survey reviews the state-of-the-art of DC ultra-fast charging stations, SST transformers, and DC ultra-fast charging stations based on SST. Ultra-fast charging definition and its requirements are analyzed, and SST characteristics and applications together with the configuration of power electronic converters in SST-based ultra-fast charging stations are described. A new classification of topologies for DC SST-based ultra-fast charging stations is proposed considering input power, delta/wye connections, number of output ports, and power electronic converters. More than 250 published papers from the recent literature have been reviewed to identify the common understandings, practical implementation challenges, and research opportunities in the application of DC ultra-fast charging in EVs. In particular, the works published over the last three years about SST-based DC ultra-fast charging have been reviewed.

Fast Battery Charger For Electric Vehicle With Solar Energy

Abstract: The paper goes through the fundamentals of fast EV battery charging equipment as well as difficulties related to charging installations for road electric vehicles. The findings of the study are based on the prospect of EV charging stations being unified in smart networks, which connect the main grid with distributed power plants, renewable energy sources, stationary electrical storage devices, and electric loads. The study will look at the characteristics of several types of DC storage devices that will be used in stationary and on-board applications. A user-selectable charging current rate is illustrated in its simplest form. The ultra-fast DC ev battery charging architecture was also given special examination, as it appears to be a viable solution to the problem.

A New TiO with in-Situ Transformed Rutile TiO2 Nanothorns As a Superb Anode Material for Lithium-Ion Battery

Developing high-performance anodes is highly desired to meet the recent ever-increasing demands for lithium-ion battery (LIB). Herein we report a uniquely integrated hybrid structure of rutile TiO2 (r-TiO2) nanothorns in situ grown over a new porous and conductive TiO core, which is generated from pyrolysis of anatase TiO2 with Mg metal at 650℃. The new hybrid exhibits superb LIB performance as an anode with high reversible capacity and almost no capacity decay during 1000 cycles at a high current density of 20 C (4000 mA g-1). Two independent reactions of intercalation and pseudocapacitive interaction are confirmed to occur in the composite of the r-TiO2 and TiO, respectively. In particular, the excellent rate capability along with long cycle life enables the new hybrid to have ultrafast charging of the system. Furthermore, the hybrid with the job-sharing property exhibits stable charge-discharge performance over a wider potential window range of 0.01 to 3.0 V, particularly even in the low potential range of 0.01~1.0 V, which usually causes irreversible Li-intercalation and rapid capacity decay for pristine TiO2. All the properties including the wider potential window allows the hybrid to realize the highest electrochemical performance that titanium oxides have ever achieved so far.

Photovoltaic and battery systems sizing optimization for ultra-fast charging station integration

The installation of Ultra-Fast Charging stations (UFCS) is of vital importance to enhance and support the global shift to electric mobility. However, since UFCSs require a huge amount of energy in short period of time, their integration with the energy transmission and distribution grids will lead to a considerable number of technical challenges. To mitigate these negative aspects the incorporation of a Photovoltaic (PV) power plant and a Battery Energy Storage System (BESS) in the station systems seems crucial. In this paper an optimization study to find the size of these additional components is carried out. The final aim is to find their optimal dimensions to make the integration the most convenient as possible from an economic point of view. To achieve such a purpose, a single-objective optimization problem is simulated. The objective function aims to maximize the Net Present Value (NPV) of the overall charging station. The single-objective function is optimized through a genetic algorithm (GA) and the optimization toolbox embedded in the MATLAB software has been used to run the proposed optimization. The results highlight how the configuration complemented with the PV plant and the BESS is better from a technical-economic perspective. As a matter of fact, the profitability of such UFCS will be 7.5 % higher than the solution without additional components.

Three-Dimensional, Submicron Porous Electrode with a Density Gradient to Enhance Charge Carrier Transport.

Rapid charging capability is a requisite feature of lithium-ion batteries (LIBs). To overcome the capacity degradation from a steep Li-ion concentration gradient during the fast reaction, electrodes with tailored transport kinetics have been explored by managing the geometries. However, the traditional electrode fabrication process has great challenges in precisely controlling and implementing the desired pore networks and configuration of electrode materials. Herein, we demonstrate a density-graded composite electrode that arises from a three-dimensional current collector in which the porosity gradually decreases to 53.8% along the depth direction. The density-graded electrode effectively reduces energy loss at high charging rates by mitigating polarization. This electrode shows an outstanding capacity of 94.2 mAh g-1 at a fast current density of 59.7 C (20 A g-1), which is much higher than that of an electrode with a nearly constant density gradient (38.0 mAh g-1). Through these in-depth studies on the pore networks and their transport kinetics, we describe the design principle of rational electrode geometries for ultrafast charging LIBs.

Enabling 100C Fast-Charging Bulk Bi Anodes for Na-Ion Batteries.

It is challenging to develop alloying anodes with ultrafast charging and large energy storage using bulk anode materials because of the difficulty of carrier-ion diffusion and fragmentation of the active electrode material. Herein, a rational strategy is reported to design bulk Bi anodes for Na-ion batteries that feature ultrafast charging, long cyclability, and large energy storage without using expensive nanomaterials and surface modifications. It is found that bulk Bi particles gradually transform into a porous nanostructure during cycling in a glyme-based electrolyte, whereas the resultant structure stores Na ions by forming phases with high Na diffusivity. These features allow the anodes to exhibit unprecedented electrochemical properties; the developed Na-Bi half-cell delivers 379mAhg-1 (97% of that measured at 1C) at 7.7Ag-1 (20C) during 3500 cycles. It also retained 94% and 93% of the capacity measured at 1C even at extremely fast-charging rates of 80C and 100C, respectively. The structural origins of the measured properties are verified by experiments and first-principles calculations. The findings of this study not only broaden understanding of the underlying mechanisms of fast-charging anodes, but also provide basic guidelines for searching battery anodes that simultaneously exhibit high capacities, fast kinetics, and long cycling stabilities.

An angstrom-level d-spacing control of graphite oxide using organofillers for high-rate lithium storage

•Layer spacing greatly affects the rate performance of batteries •Interlayer engineering with an angstrom-level precision (7.4–13 Å) is achieved •Rapid charging with high lithium storage capacity is realized •Interlayer-performance relationship for fast Li+ diffusion kinetics is provided To increase the viability of electric vehicles for the general population, it is critically important that rechargeable batteries are designed to support rapid charging, which is as important as increasing their energy density. However, commercial lithium-ion batteries (LIBs) encounter a ceiling of rate capability due to the sluggish intercalation kinetics of graphite anodes originated from their narrow interlayer spacing. Here, we report on graphite oxide frameworks (GOFs), whose interlayers are enlarged between 7.4 and 13 Å via a solvothermal reaction employing α,ω-diamino organic fillers. The GOFs offer ultrafast charging properties with a high lithium storage capacity of 370 mA h g−1 (at 3,000 mA g−1). In addition, we could determine the optimum interlayer spacing of layered electrode materials, at which the barrier for Li+ transport could be minimized. Altogether, our findings provide deep insight for the rational design fast chargeable LIBs with electrodes based on layered materials. To increase the viability of electric vehicles for the general population, it is critically important that rechargeable batteries are designed to support rapid charging, which is as important as increasing their energy density. However, commercial lithium-ion batteries (LIBs) encounter a ceiling of rate capability due to the sluggish intercalation kinetics of graphite anodes originated from their narrow interlayer spacing. Here, we report on graphite oxide frameworks (GOFs), whose interlayers are enlarged between 7.4 and 13 Å via a solvothermal reaction employing α,ω-diamino organic fillers. The GOFs offer ultrafast charging properties with a high lithium storage capacity of 370 mA h g−1 (at 3,000 mA g−1). In addition, we could determine the optimum interlayer spacing of layered electrode materials, at which the barrier for Li+ transport could be minimized. Altogether, our findings provide deep insight for the rational design fast chargeable LIBs with electrodes based on layered materials.

An ultra-fast charging strategy for lithium-ion battery at low temperature without lithium plating

Conventional charging methods for lithium-ion battery (LIB) are challenged with vital problems at low temperatures: risk of lithium (Li) plating and low charging speed. This study proposes a fast-charging strategy without Li plating to achieve high-rate charging at low temperatures with bidirectional chargers. The strategy combines the pulsed-heating method and the optimal charging method via precise control of the battery states. A thermo-electric coupled model is developed based on the pseudo-two-dimensional (P2D) electrochemical model to derive charging performances. Two current maps of pulsed heating and charging are generated to realize real-time control. Therefore, our proposed strategy achieves a 3 C equivalent rate at 0 °C and 1.5 C at −10 °C without Li plating, which is 10–30 times faster than the traditional methods. The entropy method is employed to balance the charging speed and the energy efficiency, and the charging performance is further enhanced. For practical application, the power limitation of the charger is considered, and a 2.4 C equivalent rate is achieved at 0 °C with a 250 kW maximum power output. This novel strategy significantly expands LIB usage boundary, and increases charging speed and battery safety.

TiN nano arrays on nickel foam prepared by multi-arc ion plating for fast-charging supercapacitors

Physical vapor deposition (PVD) technologies have been widely used to produce metal nitride films on planar substrate for electrode of ultrafast charging supercapacitors. However, planar electrode structure greatly limits the energy density of device. This work, for the first time, employs multi-arc ion plating (MAIP) to efficiently prepare titanium nitride (TiN) nano arrays on 3D current collector (i.e., nickel foam). The array morphology, composition, crystal structure, electrical and electrochemical properties of TiN as a function of working pressure are investigated. The optimized electrode exhibits a large specific capacitance of 90.18 F g−1 and a good stability with capacity loss of 11.9% after 10,000 charge-discharge cycles at 1 A g−1. The assembled symmetrical supercapacitor can achieve a high energy density of 4.72 Wh kg−1 with a power density of 800 W kg−1 under current density of 1 A g−1. The general findings open a new and promising strategy in facile and efficient fabrication of electrode materials towards ultrafast charging supercapacitors.

Last developments in polymers for wearable energy storage devices

Last developments in polymers for wearable energy storage devices

In-situ growing polyaniline nano-spine array on FeVO4 nanobelts as high-performance rechargeable aluminum-ion battery cathode

High-performance rechargeable aluminum-ion (Al-ion) battery has received broad attention for ultrafast charging applications. Here, we develop a FeVO4@polyaniline (PANI) nanobelt composite composing of in-situ growing PANI nano-spine array on FeVO4 nanobelts, which display an excellent electrochemical performance as Al-ion battery cathode. After cycling 300 cycles at 0.3 A g−1, the specific capacity of the FeVO4@PANI nanobelts remains 300 mAh g−1. The rate-performance of the FeVO4@PANI nanobelts keeps stable after cycling three rounds. In addition, the FeVO4@PANI displays a Coulombic efficiency of 98.8% and a specific capacity of 268.6 mAh g−1 after 200 cycles at a low temperature of −10 °C. In addition, galvanostatic intermittent titration technology (GITT) measurements and density function theory (DFT) calculations indicate the FeVO4@PANI composite exhibits improved transport dynamics of both ions and electrons, displaying its promising application for developing many other emerging energy-storage composites and systems.

Practicality of methyl acetate as a co-solvent for fast charging Na-ion battery electrolytes

Rapid research and technological improvements on Na-ion batteries (NIBs) are making them the most practicable complementary device for lithium-ion batteries (LIBs). Moreover, the high Na-ion diffusion kinetics offers several fast charging electrode materials that are attractive for high power applications. Lowering interphase and charge transfer resistances via innovative electrolytes design, while not scarifying lifetime, is however essential to secure such applications. Herein, we report the effect of low viscous ester based co-solvents in improving the conductivity of Na-ion based electrolyte. Our new electrolyte formulation shows excellent power capability charging the 18650 cell to 84% state of charge (SOC) within ∼10 min. Additionally it improved low temperature cyclability, but with a slightly reduced high temperature performance against our co-solvent free electrolyte. We believe that the guideline taken here will pave the way towards finding a better compromise between ultrafast charging and high temperature applications for reaching optimum performance.

Design and preparation of salt hydrate/ graphene oxide@SiO2/ SiC composites for efficient solar thermal utilization

Efficient solar thermal utilization has attracted extensive attention because it effectively alleviates carbon dioxide emissions and environmental pollution. Phase-change material (PCM) energy storage technology has been regarded as the most promising in improving its efficiency. Toward higher energy utilization efficiency, how to realize conversion and storage of solar energy into PCM is becoming progressively important. Herein, we developed low-cost and stable sodium acetate trihydrate (SAT, salt hydrate PCM) with ultra-fast solar energy charging efficiency by integrating photothermal and thermal conductivity materials. Specifically, a graphene oxide@SiO 2 (GS) nanocomposite fabricated by a novel modified Stober method was employed as the nucleating agent and photothermal conversion enhancers for SAT. The supercooling degree of SAT can be reduced to 0.5 °C from 32.0 °C with the addition of 1.0 wt% GS, while the solar energy charging efficiency of SAT was increased by 92.5% when it is synergistically augmented by integrating GS and silicon carbide (SiC) foam. This study results indicate that the prepared SAT-GS-SiC composite with an enthalpy of 193.2 J/g can be potentially used to efficiently utilize solar energy. A novel PCM composite with low supercooling, high thermal conductivity, and photothermal conversion efficiency was facilely synthesized. • Graphene oxide and SiO 2 (GS) composite with excellent photothermal conversion efficiency was synthesized. • Supercooling degree of sodium acetate trihydrate (SAT) could be reduced to 0.5 °C with the addition of 1.0 wt% GS. • Thermal conductivity of SAT improved by 184.5% after integrating GS and silicon carbide (SiC) foam. • Photothermal conversion efficiency of SAT-GS-SiC composites could reach to 92.5%.

Materials and systems for polymer-based Metallocene batteries: Status and challenges

Modern society is highly dependent on portable electronics powered by rechargeable batteries that are not only fulfilling the basic requirements such as fast charging and durability but also overcome the environmental issues of current lithium-ion batteries. Moreover, the required miniaturization of e.g. communication systems or sensors in mobile, wearable, or implantable devices needs optimization of the architecture, thus battery technologies that are entirely shape-conformable and bendable without loss in energy and current density. Organometallic battery materials offer certain characteristics such as ultrafast charging, flexibility, compatibility with organic and aqueous electrolytes, and tunable cell voltage, which make them interesting alternatives to replace conventional metals as electroactive components while taking advantage of the bifunctional characteristics of metal ions and organic frameworks. This review presents an overview of the research on the oligo/polymeric organometallic materials for anodic and cathodic battery application and discusses the contribution of auxiliary components. Particularly the often necessary addition of conductive fillers represents a serious obstacle against the development of organometallic batteries. Moreover, the disadvantage of volume change upon redox cycling in organometallic batteries is discussed.