Synthesis And Electrochemical Properties Of Modified Metal Skeletons For Li Metal Aondes

Lithium?Li?metal is widely considered as one of the most promising anode materials due to its high theoretical capacity(3860 mAh g^-1 or 2061 mAh cm^–2)and low electrode potential?-3.045 V?.However,due to its high electrochemical reactivity and hostless characteristics,lithium metal easily grows lithium dendrites and undergoes infinite volume changes during Li plating/stripping,which leads to battery failure.At present,the modification of Li anodes mainly includes adding electrolyte additives,designing artificial SEI,adopting solid electrolyte,and introducing 3D current collector.The introduction of3D current collectors can not only effectively inhibit the growth of lithium dendrites,but also alleviate volume changes.Inspired by this,we introduced metal foam as a 3D porous current collector and modified it to significantly improve the Li plating/stripping behavior and electrochemical performance.A 3D current collector with hierarchical copper fibers grown vertically on the copper foam skeleton?HCF/CF?,which has significantly increased specific surface area and porosity.Meanwhile,the Cu fiber with numerous protuberances secondary structure can provide the electrochemical active sites,which sever as charge centers to induce Li uniform nucleation and deposition on HCF/CF skeleton.Compared with the pristine copper foam,HCF/CF has a Coulomb efficiency of 98%after 200 cycles.The assembled symmetrical battery shows a stable cycle of about 820 h at 1 mA cm².The layered MXene anchored on copper foam?MXene@CF?significantly achieved stable Li electrochemical plating/stripping.The strong Coulomb interaction between MXene and lithium leads to uniform Li nucleation and horizontal deposition along the substrate surface.At the same time,the fluorinated SEI formed by abundant fluorine surface functional groups during the lithiation stage effectively regulated the Li deposition behavior.The MXene@CF-based symmetrical battery can stably cycle for more than 1000 h at a current density of 1 mA cm^-2,while exhibiting a deep plating/stripping capacity of up to 10mAh cm^-2.Co₃O₄ nanosheets were prepared by MOF-derived to modify the foam nickel framework?Co₃O₄/NF?,which was served as lithophilic host to fabricate Li composite anode by molten-Li infusion.Compared with the bare foam nickel,the Co₃O₄/NF skeleton has significantly improved lithium affinity.The molten lithium penetrated into the Co3O4/NF in a short time,and the nanosheet array structure of the Co₃O₄/NF was well maintained during the injection of the molten Li.The Co/NF-Li composite anode maintained a low voltage overpotential?25 V?in a stable cycle of more than 500h.When matched with LiFePO₄ cathodes,Co/NF-Li also showed significantly improved cycle stability and rate performance.