Iron Oxide-based Materials As Anode For Lithium Ion Battery

Lithium-ion batteries（LIB_S）.As renewable and green energy device,it has attracted huge attention in recent years.Although the research of anode materials has made great progress in the field of lithium-ion batteries,its energy/power density and cycle performance still can not meet the needs of the growing electrochemical energy storage devices.Therefore,it is still a very challenging and urgent work to explore new high-performance anode materials.Due to the high theoretical specific capacity of iron oxide-based materials,iron is rich in reserves,cheap and easy to obtain.Iron oxide-based anode materials are a good candidate material for lithium-ion batteries.（1）The mesoporous α-Fe₂O₃/CaCO₃ nanoparticles have been prepared from the mixture of hydroxide and ethylene glycol via a facile solvothermal method followed by sintering at 500℃in air atmosphere.When used as anode material for lithium-ion batteries,the mesoporousα-Fe₂O₃/CaCO₃nanoparticle shows great cycling stability,excellent rate capability,and improved specific capacity,which can be ascribed to the beneficial effects of the nanocomposite,the unique mesoporous structure and the pseudocapacitive contribution.（2）The orthorhombic CaFe₂O₄ microrod has been facilely synthesized via a moderate precipitation–calcination process.Structural features and electrochemical performance of the CaFe₂O₄have been investigated.When used for lithium–ion battery,the moderate surface energy of CaFe₂O₄microrod is benefit for preventing material agglomerate.CaFe₂O₄microrod displays the great low-temperature lithium–ion storage ability even tested at-20℃get exceed 100m Ah g^-1reversible specific capacity.Their room temperature electrochemical performance is also great,and the specific capacity contribution with 63–74%/96–98%of first/third cycles are driven by surface controlled pseudocapacitive.（3）In this work,a hybrid strategy for preparing a mesoporous Ca₂Fe₂O₅/α-Fe₂O₃nanocomposite has been demonstrated to exhibit great electrochemical performance as anode materials for lithium-ion batteries.The mesoporous Ca₂Fe₂O₅/α-Fe₂O₃nanocomposite has been synthesized through the mixture of Ca/Fe-hydroxides and deionized water via a facile solvothermal process followed by calcination at 700℃with air atmosphere.The prepared mesoporous Ca₂Fe₂O₅/α-Fe₂O₃nanocomposite shows great rate capability,excellent cycling stability,and high specific capacity associated with surface capacitance-controlled capacity.The high performance can be ascribed to the beneficial effects of the unique mesoporous nanocomposite,which buffers the volume change during electrode reactions,increases the contact area of the electrode/electrolyte,facilitates electrolyte diffuse and favors Li⁺ transport.