What could explain a much higher F1 score in comparision to accuracy score?
You have imbalanced classes. Notice that your accuracy is very close to your precision, and quite dissimilar to your recall. This means that your precision (accuracy of positive predictions) is dominating the overall accuracy measure - nearly all of the cases in your data are classified as positive, so the accuracy among predicted positives is almost equivalent to the accuracy among all cases. 

The F1 score is the harmonic mean of precision and recall, so it's a class-balanced accuracy measure. You have better performance on the minority class than the majority class, which is evidenced by the nearly equivalent accuracy and precision, and much higher recall.