Cut off and discard tips of chicken wings. Cut wings at joints to form 24 pieces; sprinkle with salt and pepper.
In a 3 1/2- or 4-quart slow cooker, combine wing pieces and broth. Cover and cook on low 4 to 5 hours or high 2 to 2 1/2 hours, stirring once halfway through.
Meanwhile, in a small bowl, stir together hoisin sauce, soy sauce, rice vinegar, and sriracha and set aside.
Preheat broiler. Line a 15×10-inch baking pan with foil. Using tongs, transfer wings to prepared pan; discard cooking liquid. Broil wings 4 to 5 inches from heat, 8 minutes, turning once. Toss wings with one-fourth of sauce. Broil 3 to 5 minutes or until sauce is thickened and wings are lightly browned. Toss wings with another one-fourth sauce. Serve with remaining sauce.