Fuel Cells | A-level Chemistry | OCR, AQA, Edexcel
24.1 هزار بار بازدید -
5 سال پیش
-
Fuel cells in a Snap!
Fuel cells in a Snap!
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The key points covered in this video include:
1. Uses for cells
2. Alkaline hydrogen fuel cells
3. Acidic hydrogen fuel cells
4. Pros and cons of hydrogen fuel cells
Uses for Cells
Chemical cells are used a lot in everyday life. Non-rechargeable Cells. These give us electrical energy until the chemicals within them have reacted fully and then they are disposed of. Rechargeable cells. The chemicals react and generate electricity. When we apply a potential difference in the opposite direction and the chemicals regenerate. Examples: Nickel and cadmium (Ni-Cad) used as rechargeable batteries. Lithium-ion batteries used in laptops and mobile telephones. Risks include being toxic if ingested and can also malfunction and explode.
Fuel Cells
Rather than having a stock of chemicals, fuel cells are externally supplied with the chemicals they need for the reaction. The cells can provide electrical energy as long as they are supplied with fuel. Alkaline Hydrogen Fuel Cells. Hydrogen and oxygen flow in and react, and water flows out. The electrolyte remains in the fuel cell and facilitates the flow of OH-. The fuel doesn’t have to be hydrogen - similar reactions can take place with hydrogen rich fuels like methanol.
Acidic Hydrogen Fuel Cell
Acidic Hydrogen Fuel Cells have an acidic electrolyte rather than alkaline so H+ ions flow to connect the two terminals. Hydrogen and oxygen flow in and react, and water flows out still. The electrolyte remains in the fuel cell and facilitates the flow of H+. The fuel doesn’t have to be hydrogen gas - similar reactions can take place with hydrogen rich fuels like methanol.
Pros and Cons of Hydrogen Fuel Cells
The two main advantages of hydrogen fuel cells are: 1. They are more efficient than burning fossil fuels 2. They only release water as a waste product which is not harmful. The main disadvantage of a hydrogen fuel cells is that we need energy to build them and to produce the hydrogen and this energy must still come from fossil fuels.
Summary
We’ve seen that chemical cells are used for disposable batteries and rechargeable batteries
Alkaline hydrogen fuel cells combine hydrogen and oxygen which they receive from external sources and the reaction generates electricity
Acidic hydrogen fuel cells combine hydrogen and oxygen which they receive from external sources and the reaction generates electricity
Unlock the full A-level Chemistry course at http://bit.ly/2lSE4f1 created by Barney Fidler, Chemistry expert at SnapRevise.
SnapRevise is the UK’s leading A-level and GCSE revision & exam preparation resource offering comprehensive video courses created by A* tutors. Our courses are designed around the OCR, AQA, SNAB, Edexcel B, WJEC, CIE and IAL exam boards, concisely covering all the important concepts required by each specification. In addition to all the content videos, our courses include hundreds of exam question videos, where we show you how to tackle questions and walk you through step by step how to score full marks.
Sign up today and together, let’s make A-level Chemistry a walk in the park!
The key points covered in this video include:
1. Uses for cells
2. Alkaline hydrogen fuel cells
3. Acidic hydrogen fuel cells
4. Pros and cons of hydrogen fuel cells
Uses for Cells
Chemical cells are used a lot in everyday life. Non-rechargeable Cells. These give us electrical energy until the chemicals within them have reacted fully and then they are disposed of. Rechargeable cells. The chemicals react and generate electricity. When we apply a potential difference in the opposite direction and the chemicals regenerate. Examples: Nickel and cadmium (Ni-Cad) used as rechargeable batteries. Lithium-ion batteries used in laptops and mobile telephones. Risks include being toxic if ingested and can also malfunction and explode.
Fuel Cells
Rather than having a stock of chemicals, fuel cells are externally supplied with the chemicals they need for the reaction. The cells can provide electrical energy as long as they are supplied with fuel. Alkaline Hydrogen Fuel Cells. Hydrogen and oxygen flow in and react, and water flows out. The electrolyte remains in the fuel cell and facilitates the flow of OH-. The fuel doesn’t have to be hydrogen - similar reactions can take place with hydrogen rich fuels like methanol.
Acidic Hydrogen Fuel Cell
Acidic Hydrogen Fuel Cells have an acidic electrolyte rather than alkaline so H+ ions flow to connect the two terminals. Hydrogen and oxygen flow in and react, and water flows out still. The electrolyte remains in the fuel cell and facilitates the flow of H+. The fuel doesn’t have to be hydrogen gas - similar reactions can take place with hydrogen rich fuels like methanol.
Pros and Cons of Hydrogen Fuel Cells
The two main advantages of hydrogen fuel cells are: 1. They are more efficient than burning fossil fuels 2. They only release water as a waste product which is not harmful. The main disadvantage of a hydrogen fuel cells is that we need energy to build them and to produce the hydrogen and this energy must still come from fossil fuels.
Summary
We’ve seen that chemical cells are used for disposable batteries and rechargeable batteries
Alkaline hydrogen fuel cells combine hydrogen and oxygen which they receive from external sources and the reaction generates electricity
Acidic hydrogen fuel cells combine hydrogen and oxygen which they receive from external sources and the reaction generates electricity
5 سال پیش
در تاریخ 1398/06/26 منتشر شده
است.
24,101
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