The application of micro-systems, designed to contain monitoring or actuating devices is often hampered by energy supply. For systems with low power demands, the use of implanted battery and inductive links for wireless energy transfer to the remote system is widely acknowledged solution. But these energy supply system are limited by the energy shortage and inductive coils alignment. The misalignment of wireless energy transfer loops causes the low energy transfer efficiency and inexact induced potential. Although the implanted battery can offer more stable energy supply, the shortage in energy storage limited its application and durability. In this work, we developed the wireless microwave charging module to overcome the disadvantages of previous methods. The wireless microwave charging module can charge the implanted lithium ion battery in a suitable distance by tuning the power input and the implanted lithium ion battery shows excellent cycleability after 20 cycles of wireless charging. Although the conversion of the wireless microwave charging is only 2-5%, it can be improved by using other designs of antenna (microwave generation part) and rectify antenna (receive and conversion part). The cell performance of the spinel compound for the wireless energy transfer is better than that of the layered compound. (c) 2005 Elsevier B.V. All rights reserved.