**5. Disadvantages of electric engines**

## **5.1 Battery**

The typical lithium-ion battery is utilized in electric aircrafts can be associated with hazards such as short-circuit and chemical leakage. There are battery chemistries that perform significantly better than current lithium-ion but are not available in the market. The automotive industry is utilizing hydrogen fuel cells and other forms of energy storage. The flow battery, which NASA is exploring for the Aquifer project, is one illustration of novel energy storage within the early stages of development.

#### **5.2 Weight**

Super-lightweight carbon-fiber construction methods can be used to make airplanes lighter. A better design can be used to reduce required power. For the longer endurance mission requirements of the largest aviation market segments, a hybrid solution that incorporates a small jet-fuel-powered auxiliary power unit can be utilized. While avoiding the expense and weight of an all-electric battery-powered aircraft, this solution offers improved efficiency at a lower cost. The advantages of electric propulsion will be augmented by jet fuel's high energy density. Additionally, lithium-ion batteries, which are lighter, can be utilized.

#### **5.3 Range**

Utilizing electric planes will not be feasible due to their limited range, despite the environmental and financial benefits of not using fossil fuels and the emissions that come with it. Electric planes have the same range as cars on the road, which ranges from 160 to 400 kilometers.

#### **5.4 Thermal runaway**

The electrical drive for an aircraft engine must be thermally stable and reliable to pass airworthiness regulations and be deemed safe for flight. Various electrical concepts can be used to design a fully electric aircraft. With regards to the existing electric engine architecture, the motor does not have a robust high torque and insufficient power density under heavy payloads.
