Nitecore just announced a new battery with an integrated USB-C charger. Nitecore products can be found on Amazon.
UFZ100
SpecificationsType: Rechargeable Li-ion Battery
Model: UFZ100
Voltage: 7.2V
Capacity: 2250mAh
Energy: 16.2Wh
Operation Temperature:
Charge: 0℃~45℃ (32℉~113℉)
Discharge: -20℃~60℃ (-4℉~140℉)
Dimensions: 52mm x 38.7mm x 22.5mm (2.05″ x 1.52″ x 0.89″)
Compatible Models: SONY α7 III, α7R III, α7R Ⅳ, α7S III, α9 (ILCE-9), α9 II, α6600, α7C, α1, FX3, α7 Ⅳ
*Please refer to the original battery compatibility for more compatible models