Most of the high-capacity positive-electrode materials are Li-deficient
and require the use of a Li-metal electrode or prelithiation.
Herein, we report a novel electrolytic cell in which the Si electrode
can be prelithiated in a well-controlled manner from Li containing
aqueous solution in a Li-metal-free way. MnOx/Si
and S/Si Li-ion full cells were assembled by using the prelithiated
Si negative electrodes, which resulted in high specific energies
of 349 and 732 Whkg¢1, respectively. The MnOx/Si full cell
still retains 138 Whkg¢1 even at a high specific power of
1710 Wkg¢1. This is the first report of a whole process of
making a full Li-ion battery with both Li-deficient electrodes
without the use of Li metal as the Li source. This novel prelithiation
process, with high controllability, no short circuiting,
and an abundant Li source, is expected to contribute significantly
to the development of safe, green, and powerful Li-ion
batteries.