IMPROVING THE EFFICIENCY OF CHARGING EVS
- 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 number of electric vehicles has increased significantly. More than 150,000 electric vehicles have been sold in the United States since 2012 (Sear et al., 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 EVs, which will raise the uncertain influence in the power grid operation (Zheng et al, 2017). This will result in new challenges to 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). 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 EVs. 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. Previous studies also 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.
- Literature Review
2.1 Battery Material
Past literature has discussed the impact of electric vehicle battery materials on charging efficiency. Battery materials for electric vehicles, such as battery electrode and electrolytes. Some of these researchers believe that battery materials have a positive effect on the charging efficiency of electric vehicles. To make the use of electric vehicles viable, fast charging through the use of high voltage or high current mode has been adopted, but it might result in excess heating that can be problematic (Zhao et al., 2019). The vehicle battery technology should be able to meet the electrochemical and the thermal demands of the fast charging technology, the process is achieved through the macroscopic charging technology (Tomaszewska et al, 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. Especially 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). 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 et al., 2018).
Alternatively, supercapacitors can be used to perform functions performance by high-performance batteries. Power losses are reduced if supercapacitors(electric double-layer capacitors) 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 efficiency of charging improved when supercapacitors are used as a power source for electric cars.
Some existing literature has provided important theory and supported for the research. Zhao et al. (2019), Tomaszewska et al. (2019) and Kim et al. (2018) believe that battery electrode and electrolytes can improve the efficiency of charging of EV. However, Hori (2012) points out that supercapacitors also can improve the efficiency of charge. However, due to the size of sample is small, the author has some limited results. In the same way, most of the referred documents are only for battery electrode and electrolytes.
2.2 Charging Station
There are several literature analyses and researches on the relationship between the charging station and the efficiency of charging EVs. The location and management of charging stations will be essential in determining the efficiency of charging electric vehicles. 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 crash with the system peak (Mu et al., 2012). Moreover, 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). 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 studied by Wang et al(2016) and Martínez-Lao et al(2017). 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 et al., 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).
Existing literature presents relevant study data and conclusions for the research. For example, managing users’ charging time and power, other interactions with the power grid (Wang et al., 2016) and price improvements during the off-peak hours and the use of an intelligent management system and smart grid (Martínez-Lao et al., 2017) can improve the efficiency of charging EVs.the battery exchange system (Martínez-Lao et al., 2017). The study used simple sampling.
2.3 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 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. In order 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，the fast charging of EV has been adopted. 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 et al., 2017).
Another researcher showed that 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 et al., 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.
Summarily, several existing literature explains the improvement of efficiency of charging EVs with high-level charging infrastructure (Sears et al., 2014) and (Aziz et al., 2017) is positive. Instead, some literature suggests that The harmonization of connectors, in conjunction with communication protocols, will help with the development of quick chargers (Genovese et al., 2015). However, the method of sampling is too simple, which has some limitations and the results might distort. In addition, there is no systemic survey presenting the relationship between the harmonization of connectors and the efficiency of charging EVs.
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 combining the three charging methods, record and compare the charging efficiency. Record data about the energy received by the charging unit and the power consumed by the battery. The efficiency of level 1 and level 2 EVSE will be compared to compare 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 efficiency.
H2: Widespread network of charging stations improve EV batteries charging efficiency.
H3: Level 2 EVSE is more efficient as a charging system than a level 1 charging infrastructure.
METHODOLOGY
With charging and improving the efficiency of Electric Vehicles batteries being a wide topic, several methods may be used for research. These methods may include; experiments, surveys, questioners and interviews, observation or even a combination of all of these methods. To investigate on how to improve the charging capacity of the electric vehicles’ batteries, the following three research methods will be discussed.
Materials
For any research method to be executed, all the necessary tools need to be collected. The observation, which is always easy to execute, requires the following features; first is eyesight. It is with the eye that seeing is possible. The second feature is the plan for the research—this aids in preparing a good schedule, thus reducing the wastage of time. Planning makes the researcher aim only for what is essential, leaving behind details that are not relevant. This results in less time wastage, and motivation towards achieving the intended goal is also acquired. The third key feature is the aim of the research. This provides a specific direction for the study and also keeps the researcher focused on the task at hand. It even through identifying the aim that planning for the observation practice is done. The last observation feature is the pen and paper or preferably a recording device. The human mind is forgetful. It may forget very vital details when they are needed the most. Findings from the observation practice are recorded, and thus the information can be transferred without excluding any crucial information.
Experiments are ambiguous and complicated and thus require very many tools and features. First, a lab is needed. A constant source of power also is required. The power source for Electric Vehicle Battery should be more than one, mostly two. All these power sources provide power to the electric motor. Third, a load imitator and a propulsion drive imitator is required for formulating the Drive Window, which, is usually the key motor system under consideration. A supercapacitor is also considered very important when it comes to electric vehicle experiments. This is because it carries the power to supply a vehicle when it needs acceleration. As discussed earlier, these items for an average person may be costly to purchase or even maintained; thus, large companies often employ researchers who investigate with these materials.
The last discussed research method is the survey. For a study on electric appliances, some websites may be used as well as physical methods. One may survey the use of other research methods and note the finding in a notebook for future reference. Surveys may also be done through progressive reference to the internet, as most researchers do. The internet is usually vital in promoting research and the conveyance of necessary information. Collection of data from the internet or even through reconnaissance and observation may produce very accurate results. Tools required for this kind of survey include a pen and paper, of course, and a recording device as well as a functional computer that can access the internet and relay information without any possible leaks or sudden loss of information. Survey as a research technique however, gets even more complicated as the Electric Vehicle research gets deeper, so any researcher should be prepared to invest both time and money.
Observation.
The exportation capacity for the power, for instance, should be closely monitored to determine the charging time and repression. Observation is very necessary when doing most kinds of research. It enables an engineer or the researcher in the “Electric Vehicle” setup to see the problems or advantages for different battery types and improvement solutions. Through observation, results on the degradation capacity of the battery while charging and when the vehicle is in use can be noted. The concern in this situation is not only indicating the degradations capacity but also collecting valuable information to the tiniest of detail. To investigate the different effects that different charging patterns have on the battery, observation is vital. A slight error in the miscalculation of charging time may affect the entire improvement and electric vehicle enhancement process. It is thus noted that observation is the best and most preferred research method.
For a battery cell to successfully charge, a set of chemical reactions have to take place. These chemical reactions occur in 3 phases, namely; mass transport, transfer of charge, and the process of intercalation. These three processes support and facilitate the entire process of improving efficiency. It is thus recommended to conduct sufficient research to determine if it is fit to be used currently and in the future. It is through research that its merits and demerits are put under consideration, and a long term solution is attained. Investigating the electrolytic transfer to charging a battery is not easy. Careful observation needs to be done to be in order to identify any mistakes. Observation is also done to investigate if the electrolytes are stable. If the electrolytes are durable and relatively affordable, then the research is mainly successful, and thus mass production and manufacturing can be done.
Observation is thus a vital research method. For electric vehicles’ batteries to be improved, then the correct information on various innovations needs to be collected. The only accurate way is observation. Observation is not only necessary for researchers only, but also for developers. It is only through observation that they can note competitor products’ advancements and make advancements of their own to remain relevant in the market.
Experiments
The lithium ion battery that sustains the electric vehicles is prone to advancements if at all a perfect version is to be manufactured. Considering older and newer versions of the vehicles, the main difference is the ability to hold energy to power the vehicle and the time taken to charge and drain. The whole idea of enhancements is thus based on the batteries’ specifications. Just like any other business, every company manufacturing electric cars aims at making profits. The only way to do that without violating rules of proper business, is stepping up the manufacturing game. This thus results in developments and innovations. The first electric vehicle was created during the 1800s. This was a result of experiments. From the history records, in Netherlands, the first electric car was developed when a blacksmith tried experimenting on a battery powered vehicle and was successful. The model however, was not the best to be used. Throughout the years up-to-date, there has been an increasing number of electric vehicle sales. These vehicles keep on improving on every aspect. The successful models that are in use are all products of experiments whose chances were either success or failure. As earlier mentioned, the major determinant of a battery is determining the battery life. During development of the battery, a lot of time and resources are spend in trying to create a better and more reliable prototype. It is thus through successive collaboration of Engineers and scientists that these batteries are enhanced. Experimenting is thus a major research method. For this kind of research, unlike observation, there is a lot of time and resources needed. This thus makes experimenting a rather time consuming and expensive methods of research. Among its setbacks also include; innovative students may not be able to apply their ideas due to difficulty in accessing raw materials. It may also require a lot of legal processes that sometimes may take long proving to be very inconveniencing. The whole process of experimenting may be very risky especially if the whole thing is done in a densely populated place. When dealing with chemicals and electricity, danger is an unavoidable factor. Developing a new model that is better and more efficient thus calls for experiment indicating that it is a vital research method.
Surveys
Apart from observation and experimentation, surveying is another major research method that is important for this segment. The only way to improve the performance of something or somebody is observing its characteristics and noting key data from the investigation. In examining what to develop as appertains charging a battery, data has to be collected under different circumstances and over a given period of time. In order to identify the best charging method for the typical electric vehicle battery, data on previous models and different charging methods need to be collected. Different charging profiles need to be compared and their effect on battery life, considering the fact that the lithium ion battery is the most critical and expensive part in an electric vehicle. Some methods may save on time but not energy, others on energy but not time and other may save on neither. The difference in these charging methods and battery improvement prototypes is all determined by careful survey. An example is that, it is recommended that one should include resting periods when charging the battery. If a careful survey is done on this method of charging, then it is seen that the method saves on the battery life but is not very suitable for saving time.
These 3 methods are the most effective when it comes to investigating on how to improve efficiency of charging electric vehicles. I however feel that experimentation comes first since it is from the results of these experiments that data for survey is collected. Observation comes second since it is through observing different charging techniques that we are able to collect information. It is the comparison of the information collected over time and of different charging methods that result to survey. The steps therefore followed, depending on the resources not the urgency are; Observation, which tends to be the cheapest, survey which may take a lot of time but has factual results, then experimenting which as stated earlier, is expensive time consuming and very dangerous.
For sufficient information to be obtained, research has to be done carefully. Finding my sources of information was not easy since I had to dig deep into the internet to find books, articles and websites about the electric vehicle batteries. The information in many of these websites is for sale and thus obtaining books physically is the best way to conduct a part of survey as a research method. The observation technique however is very resourceful. Basing my research on a website; www.energy.gov, and www.Lelandwest.com the history of the electric vehicle is quite spectacular, within improvements being made in every stage, each resulting to a great outcome. The lithium ion battery in operation lately however, is a legendary improvement since it has cells which can hold a large amount of power.
Findings and Discussion
The following texts belong answer questions asked earlier on, while providing relevant evidence to the findings.
-How does battery material impact on the efficiency of charging electric vehicle batteries?
The lithium ion battery, which is commonly used in electric vehicles, is the most suitable for allowing current to flow to the battery. The electrode and electrolyte reactions that happen in a lithium ion battery to allow charge to flow is balanced and stable. Use of any other material for the electric vehicle battery may compromise a lot of details and may even result to progressive degrading of the battery with each charge. Use of other battery material may most possibility endanger the life of the car owner either during charging or travelling. Different methods that reduce degradation during charging have been invented only for lithium ion batteries. Its merits and demerits are well investigated and weighed in order to be allowed. Use of other battery materials may mess things up pretty bad since very few knowledge is attained meaning the precaution is minimal.
-Does increase in charging locations positively affect the efficiency of charging electric vehicles?
An increase in charging locations results in a positive impact on the battery life. It is through this method that the charging duration is increased. This is because, according to research, having multiple charging sessions with short durations reduces the battery degradation. The effect that occurs as a result of continuous charging is overheating. This is not healthy for the sustainability of the battery life. It is thus advised that the electric vehicle users charge the batteries while taking random but well calculated breaks. This process should be repeated until the battery is full.
-What is the correlation between charging equipment and charging efficiency in electric vehicles?
The charging equipment plays a major role in determining the battery life and charging efficiency. The charging equipment, are categorized into levels, depending on the voltage they supply and the charging speed. An electric vehicle battery requires charging while taking breaks to boost its life and prevent degradation. Some charging equipment however, do not offer space for that. For instance, the Direct Current fast charging supplies the battery with about 600 V of power. Continuous use of this equipment may result to short battery life due to the heat effect. This method, fast as it may be, is not so much preferred. The AC level 2 is the second charging equipment under consideration. It discharges a power supply worth 240 V. It is relatively safer for the battery life but it takes longer than the DC fast charger. The last charging equipment under consideration is the AC level 1. AC level 1 discharges a voltage of 120 V which is half of the AC level 2. This equipment causes very little damage to the battery and is thus the most efficient when it comes to charging. It is however very slow and time consuming. The AC level 1 is most preferred for home installation since it is way cheaper and drains lesser power. These three charging equipment however, all have effects on the battery and the difference is just time before the battery degrades to a dangerous level.
Findings
Phosphate cathodes are much more preferred in the development and upgrading of the lithium ion battery. Cobalt tends to be expensive and thus its large scale use poses as a loss to the electric vehicle companies. Phosphorus and iron are thus preferred due to their cheaper price and their incredible conducting abilities. From the entire research and essay as well, it is evident that for the lithium ion battery to suffer lesser loss, the modified charging profile is applied. This charging technique, as stated earlier, recommends that the battery should be charged with random breaks to avoid overheating. This method is the best and the safest for charging the lithium ion battery. Other advancements under the research findings is the discovery of the glass battery. According to various sources, its cells are much more different than the lithium ion battery and that it has better specifications. It is said to hold more power than the lithium ion battery and that it can withstand different environmental conditions without showing signs of error. All these improvements being made on the electric vehicle battery are all aimed at providing a better and more legit version if the Electric vehicle. With great and genius creations on the batteries performance and characteristics comes loads of money for the pioneers. It is thus recommended that the owners of these electric vehicles be careful especially with the DC faster charge system since such amounts of electricity are dangerous. It is an obvious finding that electric vehicles are more environmental friendly than the gasoline powered vehicles, and that their maintenance is cheap and affordable.
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