For improving the energy storage performance of lead-free ceramic capacitor materials based on Bismuth sodium titanate（NBT）

MgO is introduced into 0.65[Na

0.5

Bi

0.5

TiO

3

]

-0.35Sr

0.7

Bi

0.2

TiO

3

by A-site doping method. The samples of 0.65[（Na

1-

x

Mg

x

）0.5Bi

0.5

TiO

3

]

-0.35Sr

0.7

bi

0.2

Ti

O3

（BT-SBT）ceramics with different molar ratios（

x

=0.01~0.06）are prepared by solid sintering method.

It is found through SEM observation and XRD characterization that the grain size of NBT-SBT ceramics decreases first and then increases with the increase of Mg

2+

content. When the Mg

2+

incorporation amount（

x

）is 0.025

the grain size of the ceramic is minimum. The dielectric temperature spectrum and the hysteresis loop tests show that the ceramic exhibits typical ferroelectric relaxation behavior with higher dielectric constant（

ε

r

）and electric polarization strength（

P

max

）.（Na

0.94

Mg

0.06

）BT-SBT at 100 kV/cm electric field can release energy density Wrec up to 1.65 J/cm

3

the energy storage efficiency

η

is 75% and the comprehensive performance is superior to the similar NBT based ceramic samples. The results show that MgO-doped（Na

1-

x

Mg

x

）BT-SBT ceramic is a kind of high-power energy storage material with excellent efficiency

which can provide a reference for the research of high power energy storage capacitors in the field of electronic and electrical equipment.