(Ba0.85Ca0.15)(Zr0.1Ti0.9)O-3-3 wt.%Li2CO3/(Ba0.85Ca0.15)(Zr0.1Ti0.9)O-3-3 wt.%MgO (abbreviation as BCZTL/BCZTM) bilayer ceramics are prepared by the conventional solid-state reaction method. A single-perovskite structure and the diffused phase transition behavior are found in the BCZTL/BCZTM bilayer ceramics by XRD and epsilon - T curves. The bilayer ceramics show high energy storage density (W-rec) 258 mJ/cm(3) and good energy storage efficiency (eta) 82.9%. Moreover, compared with the BCZTL and BCZTM ceramics, the recoverable energy storage density of BCZTL/BCZTM bilayer ceramics has, respectively, increased by 25.8% and 10.7%. And the bilayer ceramics exhibit a good thermostability with a smaller change rate (13.38%) of W-rec. Meanwhile, the energy storage efficiency obviously increases from 84.0% at 20 degrees C to 91.6% at 100 degrees C, which indicates that the BCZTL/BCZTM bilayer ceramics have a potential application in energy storage systems.