Introduction
In light of global warming and climate change, the pressure to conserve the environment has led to the rapid development and adoption of electric vehicles. In addition, countries have also actively developed policies that support electric vehicles. Therefore, the usage of electric vehicles has increased significantly. More than 150,000 electric vehicles have been sold in the United States since 2012 ( Sears, Roberts, & Glitman , 2014). Moreover, in the coming years, electric vehicles are expected to become more widely available. The high number of electric vehicles projected in the future will result in an increase in power consumption because of the random charging of many electric vehicles, which will increase the influence of uncertain factors in the power grid operation ( Zheng, Xie, Liu, Wang, Du, & Han, 2017). This will result in new challenges to the economic operation of the power grid scheduling and control
Electric vehicles (EV) presents a sizeable new source of demand for electricity. Therefore, for sustainable adoption of these vehicles, there is a need for optimum management of the charging process through the time of use rates that promotes plugging during off-peak hours (Jin, 2018). In addition, smart charging techniques that can help flatten the demand profile can also be adopted. Furthermore, there are techniques that can be used to improve the efficiency of charging electric vehicles. First, battery materials affect the charge holding capacity of EV. The transition from using conventional batteries to using capacitors can help improve the power-retaining potential of EV. Secondly, previous studies suggest that the development of various types of charging stations in conjunction with recharge management can help regulate and facilitate a more efficient charging. The charging equipment used will also affect the efficiency of charging electric vehicles.
Delegate your assignment to our experts and they will do the rest.
Literature Review
Battery Material
To make the use of electric vehicles viable, fast charging through the use of high voltage or high current mode has been adopted. While this technology has the potential to achieve a ’10-minute full charge’; which is appealing to many users, it might result in excess heating that can be problematic ( Zhao, Wang, Chen, & He, 2019). The vehicle battery technology should be able to meet the electrochemical and the thermal demands of the fast charging technology. While the current lithium-ion battery can be quickly charged, the process is achieved through the macroscopic charging technology, which contributes to the aging of the battery material. Degradation effects as a result of thermal effects, lithium plating, and mechanical pulverization result in the reduced performance of these batteries with time ( Tomaszewska, Chu, Feng, O'Kane, Liu, Chen,... & Li, 2019). According to a study conducted by Zhao et al. (2019), the use of red phosphorous anodes can help improve the efficiency of charging by meeting the double standards of high-energy-density and fast-charging performance to a maximum degree. Besides, the platform of discharging for red phosphate related anodes is higher with minimum risk of lithium plating and thus safer. A battery with red phosphate as one of its material is expected to be more durable and charge more efficiently ( Kim, Lee, & Choi, 2018). The superior rate performance at 2500 mAh g-1 and the high-energy-density for the high lithium plating potential of 0.8V (vs. Li/Li+) makes red phosphorus a key material for developing fast-charging lithium-ion cell that can be charged more effectively (Zhao et al., 2019).
Alternatively, supercapacitors can be used to perform functions performance by high-performance batteries. Supercapacitors, which are also known as capacitors, have multiple advantages over conventional batteries, including a longer operating life and a higher power density, among others (Hori, 2012). Since electric vehicles require multiple charging and discharging per day, there is a need for a power source that has a longer life and low charging time. Therefore, supercapacitors (electric double-layer capacitors) become a suitable option. Supercapacitors have a low energy density despite the high power density. Power losses are reduced if supercapacitors are used. An electric vehicle can use up to 75% of the charged energy, which is not achievable with conventional batteries (Hori, 2012). Therefore, the short charging time, high power density, and the efficient usage of charged energy results in improved efficiency of charging when supercapacitors are used as a power source for electric cars.
Charging Station
The location and management of charging stations will be essential in determining the efficiency of charging electric vehicles. Electric vehicles charging loads are large and vary with time. Unlike other electrical demands, which are stationary, EVs cause geographically mobile demand for electricity. Furthermore, EVs are charged for a relatively longer durations, which might coincide with the system peak ( Mu, Wu, Jenkins, Jia, & Wang, 2012). Therefore, the adoption of electric vehicles have a significant impact on the power grid, and without effective network evaluation, planning, and charging management, the resultant instability of the power grid system might have a significant cost effect (Mu et al., 2014). Hence, the proper location of charging stations not only facilitates easy access to electricity but all ensure that the limited power supply is used effectively.
The adoption of smart charging in these power stations can help manage users’ charging time and power, as well as other interactions with the power grid through regulation and electricity demand ( Wang, Shen, & Zhang, 2016); Martínez-Lao, Montoya, Montoya, M. G., & Manzano-Agugliaro, 2017). Various methods can be adopted to promote effective time and power usage. For instance, the introduction of regulations to govern the usage of public power post will help regulate the power consumption by EVs. In addition, other methods, including price improvements during the off-peak hours and the use of an intelligent management system and smart grid, can help improve the effectiveness of the charging stations ( Yong, Ramachandaramurthy, Tan, & Mithulananthan, 2015). The capacity of the charging station to recharge batteries of EVs can be regulated through the use of information and communication technology. Alternatively, other recharge methods such as the battery exchange system can help reduce the time to a full charge when recharging the EV and thus making it more convenient for the EV users. The battery exchange method will only require a battery swap at the station, which takes less than a minute ( Martínez-Lao et al., 2017). The incorporation of other charging methods such as wireless charging will help make these charging stations useful to a variety of EVs. Proper distribution of charging stations and their subsequent management will help ensure access to recharge while also regulating EVs interaction with the electric system, and thus promoting effective and sustainable charging of electric vehicles.
Charging Equipment
Even after the development of a good network of charging stations, the charging equipment adopted in these stations will impact on the efficiency of charging EV batteries. The efficiency of charging will vary depending on the electric vehicle supply equipment (EVSE) used for charging these vehicles. According to Sears et al. (2014), a level 2 charging infrastructure offers consistent, efficient gains over level 1; a greater proportion of energy draw from the power grid is used to charge the EV battery when the level 2 EVSE is used. A study on the Chevrolet Volt found that level 2 EV charging is 2.7% more efficient than level 1 charging (Sears et al., 2014). A level 2 charging infrastructure can be as much as 12.8% more efficient than level 1 charging infrastructure over a short duration.
The use of fast charging systems can also help improve the effectiveness of charging posts and stations. The concentrated charging of electric vehicles can cause a decrease in the quality of electricity, including deteriorated frequency and electric voltage, as well as other power grid problems. In other to avoid the effect of excessive usage of electricity for EV research, there has been a development of technology and policies to help minimize these negative effects. Therefore, the fast charging of EV has been adopted. The high charging rate leads to low charging time. Therefore, due to the short charging period, electric vehicles do not spend a lot of time draining energy from the power grid. The use of fast charging helps reduces the electricity demand burden on the grid system as a result of EVs. In addition, batteries charged using the higher charging rates performed better as a result of the quick charging during the simultaneous charging in addition to maintaining the contracted electricity of the charger ( Aziz & Oda, 2018; Aziz & Oda , 2017). The interoperability of the electric vehicles, which can be achieved by joining EVs and charging station manufacturers, can facilitate the development of fast chargers ( Genovese, Ortenzi, & Villante, 2015). The harmonization of connectors, in conjunction with communication protocols, will help with the development of quick chargers. Provided the EV battery meets the electrochemical and thermal requirements of fast charging, the process can be used to improve the effectiveness of charging EV batteries.
Research Questions
The primary objective of the current study is to explore factors that can improve the efficiency of charging electric vehicles on time and energy. In other words, the study seeks to investigate the fastest way full recharge of EV batteries can be achieved and the effective utilization of the energy drawn from the electricity grid to recharge these batteries. Since the study wants to compare the efficiency of charging with battery material, charging station, and charging equipment, there will be three methodologies. The study will investigate the effect of fast charging on lithium. To achieve this, a Bat PaC simulation will be used. The Lithium-ion, which is the primary material on conventional batteries, will be compared with the red phosphorous anodes through simulation. Different thickness of lithium will be used to explore how the effect of charging varies with thickness. The second methodology, which investigates the effect of charging stations on the effectiveness of charging, will also be conducted using a simulation. Some of the parameters for the charging location parameter include network distribution and charging techniques. The final method will be done using six volunteer EV owners who will participate in the study. Logging devices will then be installed in their vehicle to measure the charging efficiency for every charging even. The logger will provide data on the energy received from the charging units and the amount taken up by the battery. The efficiency for level 1 and level 2 EVSE will be compared to compared the infrastructure with the highest efficiency.
The primary research questions for the project include:
How does battery material impact on the efficiency of charging electric vehicle batteries?
Does the increase in charging locations positively affect the efficiency of charging electric vehicles?
What is the correlation between charging equipment and charging efficiency in electric vehicles?
The hypothesis for the study is:
H1: The use of red phosphorus anodes as the key materials of EV batteries will improve its charging efficiencies.
H2: Widespread network of charging stations improve EV batteries charging efficiencies.
H3: Level 2 EVSE is more efficient as a charging system than a level 1 charging infrastructure.
References
Aziz, M., & Oda, T. (2018). Advanced battery-assisted quick charger for electric vehicles. In Behaviour of Lithium-Ion Batteries in Electric Vehicles (pp. 201-224). Springer, Cham.
Aziz, M., & Oda, T. (2017). Simultaneous quick-charging system for electric vehicle. Energy Procedia , 142 , 1811-1816.
Genovese, A., Ortenzi, F., & Villante, C. (2015). On the energy efficiency of quick DC vehicle battery charging. World Electric Vehicle Journal , 7 (4), 570-576.
Hori, Y. (2012, May). Novel EV society based on motor/capacitor/wireless—Application of electric motor, supercapacitors, and wireless power transfer to enhance operation of future vehicles. In 2012 IEEE MTT-S International Microwave Workshop Series on Innovative Wireless Power Transmission: Technologies, Systems, and Applications (pp. 3-8). IEEE.
Jin, N. (2018, June). Design of power state test system for electric vehicle battery. In 2018 International Conference on Smart Grid and Electrical Automation (ICSGEA) (pp. 16-19). IEEE.
Kim, N. Y., Lee, G., & Choi, J. (2018). Fast‐Charging and High Volumetric Capacity Anode Based on Co3O4/CuO@ TiO2 Composites for Lithium‐Ion Batteries. Chemistry–A European Journal , 24 (71), 19045-19052.
Mu, Y., Wu, J., Jenkins, N., Jia, H., & Wang, C. (2014). A spatial–temporal model for grid impact analysis of plug-in electric vehicles. Applied Energy , 114 , 456-465.
Mu, Y., Wu, J., Ekanayake, J., Jenkins, N., & Jia, H. (2012). Primary frequency response from electric vehicles in the Great Britain power system. IEEE Transactions on Smart Grid , 4 (2), 1142-1150.
Martínez-Lao, J., Montoya, F. G., Montoya, M. G., & Manzano-Agugliaro, F. (2017). Electric vehicles in Spain: An overview of charging systems. Renewable and Sustainable Energy Reviews , 77 , 970-983.
Sears, J., Roberts, D., & Glitman, K. (2014, July). A comparison of electric vehicle Level 1 and Level 2 charging efficiency. In 2014 IEEE Conference on Technologies for Sustainability (SusTech) (pp. 255-258). IEEE.
Tomaszewska, A., Chu, Z., Feng, X., O'Kane, S., Liu, X., Chen, J., ... & Li, Y. (2019). Lithium-ion battery fast charging: A review. ETransportation , 1 , 100011.
Wang, M., Shen, X. S., & Zhang, R. (2016). Mobile electric vehicles . Springer.
Yong, J. Y., Ramachandaramurthy, V. K., Tan, K. M., & Mithulananthan, N. (2015). A review on the state-of-the-art technologies of electric vehicle, its impacts and prospects. Renewable and Sustainable Energy Reviews , 49 , 365-385.
Zhao, H., Wang, L., Chen, Z., & He, X. (2019). Challenges of Fast Charging for Electric Vehicles and the Role of Red Phosphorous as Anode Material. Energies , 12 (20), 3897.
Zheng, J., Xie, T., Liu, F., Wang, W., Du, P., & Han, Y. (2017, October). Electric vehicle battery swapping station coordinated charging dispatch method based on CS algorithm. In 2017 IEEE 3rd Information Technology and Mechatronics Engineering Conference (ITOEC) (pp. 150-154). IEEE
