Amazon.com: USB Rechargeable AA Batteries by Pale Blue, Lithium Ion 1.5v 1560 mAh, Charges Under 2 Hours, Over 1000 Cycles, 4-in-1 USB to Micro USB Charging Cable, LED Charge Indicator, 4-Pack :
ZODIAC LITHIUM-ION BATTERIES - Zodiac
Lithium Ion batteries | Panasonic Industry Europe GmbH
Lithium Ion Battery Pack - 3.7V 6600mAh : ID 353 : $24.50 : Adafruit Industries, Unique & fun DIY electronics and kits