Preheat grill to medium-high. Place a fine-mesh nonstick grill topper on grill to heat.
Whisk lemon juice, thyme, oil, lemon zest, pepper and salt in a small bowl.
Toss scallops with 2 tablespoons of the lemon mixture; reserve the remaining mixture for basting the kebabs. Thread the scallops and the lemon wedges onto four 10-inch-long skewers (see Tip), placing 6 to 7 scallops and 2 lemon wedges on each skewer.
Lightly oil the grill rack (see Tip). Cook the kebabs, turning from time to time and basting with the reserved lemon mixture, until the scallops are opaque in the center, 8 to 12 minutes. Serve immediately.