# Impact of Temperature on Fuel Cell Work Output

• eraemia
In summary, as temperature increases, the maximum amount of work obtained from the fuel cell reaction decreases. This is because the value of ln(K) increases with temperature, making w_max more negative.
eraemia

## Homework Statement

2 H2(g) + O2(g) 2 H2O(l) K = 1.28e83

As temperature increases, does the maximum amount of work obtained from the fuel cell reaction increase, decrease, or remain the same?

1. G = -RTln(K)
2. dG = dH - tdS
3. w_max = dG

## The Attempt at a Solution

Okay, using formation values, I calculated that for this reaction, both dH and dS are < 0.

If dG = w_max (eq. 3), then w_max = -RT ln K (1 and 3)
Since ln(K) is positive, the larger the T, the more negative w_max.
Thus, as T increases, w_work decreases?

Is that right? Thanks.

eraemia said:
Thus, as T increases, w_work decreases?

Is that right? Thanks.
Sounds good.

## 1. How does temperature affect the efficiency of fuel cells?

Temperature has a significant impact on the efficiency of fuel cells. As temperature increases, the rate of chemical reactions within the fuel cell also increases, resulting in higher energy output. However, if the temperature is too high, the fuel cell components may degrade, leading to a decrease in efficiency.

## 2. Is there an optimum temperature for fuel cell operation?

Yes, there is an optimum temperature for fuel cell operation. The ideal temperature range varies depending on the type of fuel cell, but generally falls between 70-90 degrees Celsius. Operating within this temperature range allows for efficient energy production and minimizes the risk of component degradation.

## 3. How does temperature affect the lifespan of a fuel cell?

The lifespan of a fuel cell is directly affected by temperature. Higher temperatures can accelerate the degradation of fuel cell components, leading to a shorter lifespan. It is important to operate fuel cells within their specified temperature range to prolong their lifespan.

## 4. Can extreme temperatures damage fuel cells?

Yes, extreme temperatures can damage fuel cells. Extremely high temperatures can cause thermal runaway, leading to permanent damage or even failure of the fuel cell. On the other hand, extremely low temperatures can cause freezing of the electrolyte, hindering the flow of ions and reducing energy output.

## 5. How does temperature affect different types of fuel cells?

The impact of temperature on fuel cells varies depending on the type of fuel cell. For example, proton exchange membrane fuel cells operate more efficiently at lower temperatures, while solid oxide fuel cells require high temperatures for optimal performance. It is essential to consider the temperature requirements of different fuel cell types when designing and using them.

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