Preparation And Energy Storage Properties Of Lead Zirconate Based Ceramics

As an anti-ferroelectric energy storage ceramic material,lead zirconate（PbZrO₃）,is widely used in high power electronics,electrical appliances and other fields.However,due to a series of factors such as high sintering temperature and volatilization of lead,PbZrO₃ceramics prepared by solid-phase sintering method have been limited its wide application in the field of energy storage capacitors.Therefore,it is a hot topic in the current research to reduce the sintering temperature and optimize the composition while maintaining excellent energy storage performance.In this paper,nanosized PbZrO₃-based ceramic powders were successfully prepared by chemical precipitation method.The effects of lead excess,ion doping（Ti,La and Ca ions）and annealing time on the crystal structure,microstructure,dielectric properties and energy storage properties of PbZrO₃-based ceramics were systematically studied.The main research contents and results are as follows.Nanosized powders of PbZrO₃ were successfully prepared by a chemical precipitation method.It is shows that PbZrO₃ powders with good crystallization and particle size of about 40nm could be successfully synthesized with 6mol/L KOH and calcination at 700℃ for 2 h.With obtained PbZrO₃ powders,PbZrO₃ ceramics were prepared by sintering at 1150℃ with an effective energy storage density of 0.25J/cm³.The sintering temperature of 1150℃ is reduced by 200℃ compared with that of solid-phase reaction method（1350℃）.In order to inhibit the volatilization of lead and improve the effective energy storage density of PbZrO₃ ceramics,PbZrO₃ nano-powders with different lead excess were synthesized by chemical precipitation method,and then PbZrO₃ ceramics with different lead excess were prepared with the obtained powders.It is shown that when the lead excess is 10mol%,the effective energy storage density is 0.688 J/cm³,which is 244%higher than that of PbZrO₃ ceramics obtained without excessive lead.It indicates that appropriate excessive lead can effectively improve the energy storage properties of PbZrO₃ ceramics.In order to further improve the energy storage properties of PbZrO₃ ceramics,Ti,La and Ca ions were doped into PbZrO₃ ceramics.First,Ti,La and Ca ions doped PbZrO₃ceramics powders with particle size of 40 nm were synthesized under the conditions of 6mol/L KOH concentration and calcination at 700℃ for 2 h.Then,(Pb_1-3y/2-zLa_yCa_z)(Zr_1-xTi_x)O₃ ceramics were prepared by sintering the powders obtained above.It is found that when x=0.04,y=0.02,z=0.02,the effective energy storage density of(Pb_0.95La_0.02Ca_0.02)(Zr_0.96Ti_0.04)O₃ ceramics sintered at 1150℃ for 10h is 1.78J/cm³,and the energy storage efficiencyη=83%.Compared with pure PbZrO₃ ceramics,the increase is 154% and 14%,respectively.The results indicate that the energy storage properties of PbZrO₃ ceramics can be improved effectively with the extension of annealing time and the doping of Ti,La and Ca ions.