Preparation And Pre-lithiation Technology Of FeC₂O₄ Anode Composite Materials For Lithium-ion Batterie

Lithium-ion batteries are currently widely studied as energy storage devices.Graphite carbon materials make up the majority of the commercially available anode electrode materials.There is a lot of room for research and development in the field of anode electrode materials due to the need for high energy density,the variety of lithium storage modes,and the various application environments.It is essential to create new high-energy lithium-ion battery anode electrode materials.Iron oxalate has been synthesized in a variety of morphologies by controlling the crystal structure and serves as a representative anode electrode material for transition metal oxalates.It is easily prepared,has a large specific discharge capacity,and can undergo controlled morphological changes.Different iron oxalate crystal types have varying lithium storage capacities.All of them have more than twice the actual discharge specific capacity of graphite anode.Through in-depth research on the lithium storage mechanism and material modification of iron oxalate,their cycle and rate performance have been greatly improved,with good development prospects.However,due to the nature of oxalate,iron oxalate has poor electronic conductivity and variable morphological variability,and a large irreversible capacity during the initial discharge.In this study,iron oxalate is combined with nano-Ge metal,which has high conductivity and high discharge specific capacity,using an organic solvent-assisted hydrothermal method.A 3D nano germanium conductive network is created using nano Ge metal as the core to encourage iron oxalate crystallization,which enhances the material’s performance in many ways.With a first capacity retention of 90%and a specific discharge capacity of 1090m Ah g^-1 after 200 cycles at 1A g^-1,the FCO@Ge-1 electrode demonstrates exceptional lithium storage capacity.Electronic conductivity is significantly increased by the conductive fulcrum network system,which also decreases the unstable region and lessens the polarization phenomena.This composite electrode structure provides a feasible experimental scheme for improving the performance of most TMOxs with low conductivity.By designing a contact type pre-lithification experimental scheme,the elimination of the first irreversible capacity was completed,and it was discovered that the first irreversible capacity originated from the decomposition of the electrolyte and the formation of the SEI film,manifested as a voltage platform around 1.2V.In the self-discharge mechanism,the time variable and the discharge process under the cell voltage have the phenomenon of advance or lag,which has different effects on the form of lithium storage at different stages.By observing the change of particle morphology and analyzing the chemical reaction process,the time point of pre-lithiation progress is delineated.Under the premise of eliminating the first irreversible capacity,the half-cell can reach the ideal state and the full-cell performance has a substantial improvement.After exploring the contact pre-lithiation technique,the lithiation process of iron oxalate in the electrolyte atmosphere is simulated,and the electrochemical behavior of iron oxalate material is better understood,which provides an experimental scheme to adapt to the requirements of industrial production.