# Electric Vehicles: Benefits, Challenges, and Potential Solutions for Widespread Adaptation
## 2 Background
### Electric Vehicles
#### 2.3.1 Classification of Electric Vehicles  
Vehicles that operate on electricity rather than petrol or diesel fuel are known as electric vehicles (EVs). There are several EV kinds, each with a unique engine and settings [44]. According to their engine technology and settings, electric cars are categorized in the following manner in detail (Figure 4):  
Battery Electric Vehicles (BEVs): Rechargeable batteries are the only power source for BEVs, which are electric automobiles. They don't have a backup generator or a petrol engine. Due to their lack of exhaust emissions, BEVs are regarded as the most ecologically beneficial form of electric car. However, they have a constrained driving range because the battery must be recharged [45].  
Hybrid Electric Vehicles (HEVs)  
Hybrid Electric Vehicles (HEVs): HEVs are electric cars with petrol engines and electric motors. An electric motor propels the car at low speeds and during acceleration. The petrol engine takes over at higher speeds and when greater power is required. Because HEVs utilize regenerative braking to recharge their batteries, they do not require plugging in. Although they use less fuel than conventional petrol cars, they have some exhaust emissions [45].  
Plug in Hybrid Electric Vehicles (PHEVs)  
Hybrid electric vehicles (HEVs) with bigger batteries that can be recharged by plugging a charging cable into an external electric power source in addition to internally by their on-board internal combustion engine-powered generator are called plug-in hybrid electric vehicles (PHEVs). They have a finite range of operations on electric power before switching to the petrol engine. PHEVs provide the ease of daily driving without a plug while allowing for electricity usage or on short journeys [46].  
Fuel cell electric vehicles (FCEVs)  
Fuel cell electric vehicles (FCEVs): FCEVs react hydrogen gas with oxygen in the air to create power. They don't have a battery, and their sole waste is water vapor. Although FCEVs can be refueled in a few minutes and have a greater driving range than BEVs, there is still a lack of hydrogen refueling infrastructure [47].  
Extended Range Electric Vehicles (ER-EVs) are a type of electric vehicle that combines the features of a Battery Electric Vehicle (BEV) and a Plug-in Hybrid Electric Vehicle (PHEV). ER-EVs have a larger battery pack than PHEVs, which allows them to travel longer distances on electric power alone. However, once the battery is depleted, a small gasoline engine generates electricity to power the electric motor and extend the vehicle's range [48].  
ER-EVs are becoming more popular as they offer the benefits of both BEVs and PHEVs. They can be driven purely on electric power for shorter trips and travel long distances  
Figure 4: Classification of Electric Vehicles (EVs) according to engine technology and settings.  
without stopping and recharging the battery. ER-EVs are also more environmentally friendly than traditional gasoline-powered vehicles as they produce fewer emissions.  
One example of an ER-EV is the Chevrolet Volt, which has a battery range of approximately 53 miles before the gasoline engine kicks in. ER-EVs are a promising option for consumers looking for a more sustainable mode of transportation but needing the flexibility to travel longer distances.  
Each type of EV has its advantages and disadvantages. BEVs and FCEVs produce no tailpipe emissions and are considered more environmentally friendly, but their limited range and lack of infrastructure may be a challenge for some users. HEVs and PHEVs offer more flexibility and do not require new infrastructure, but they still produce some emissions and are less environmentally friendly than BEVs and FCEVs [48].