Make the brine. In a large bowl, whisk together 2 cups water, the tea and salt until the salt dissolves. Squeeze the lemon halves into the pot then add them and the chicken pieces to the pot, submerge and soak for 2 hours at room temperature.
Make the syrup. In a medium pan over medium heat, combine the tea, sugar, lemon zest, and lemon juice. Simmer until reduced and thickened like syrup. Taste and add a pinch of salt. Stir in the thyme.
Prepare to fry. In a large pot, heat 6 inches of oil until a deep-fry thermometer reaches 325° F. In a large bowl, whisk together the eggs, cayenne, a pinch of salt and a few grinds of pepper. Drain the chicken from the brine and pat dry. Dust the chicken in the flour and shake off excess. Dip each piece in the egg, then back in the flour to coat. Set on a wire rack to let the coating sink in for 15 minutes.
Fry the chicken. In batches, fry the chicken until golden brown on both sides and cooked through, 15-20 minutes, depending on the size of the piece. Remove from the oil and set on a paper towel-lined plate to drain. Drizzle with the sweet tea syrup.