Research On The Application Of Composite Electrode Based On Copper Oxide Nanowires And Self-assembled Monolayer Lithiophilic Modification For Lithium Metal Anode

As energy is an important pillar of the continuous development and progress of human society,batteries have become an extremely important means of energy storage,reducing the society’s demand for fossil energy.Lithium-ion batteries（LIBs）have gradually become a dominant market,and the graphite anode materials supporting them cannot meet human needs.Due to its unique ultra-high specific capacity characteristics,lithium metal is regarded as an anode material with important exploration value in the next generation of energy storage devices.However,to be applied in real life,there are still many problems that need to be solved,such as interface imbalance,irregular growth of lithium dendrites and volume changes of lithium metal.To solve the above problems,this paper proposes the following solutions:（1）The metal current collector is combined with a lithiophilic modification layer to form a composite lithium metal anode to improve battery performance:In the third chapter of this paper,the surface monolayer self-assembly（SAM）modification of the two-dimensional copper foil current collector was carried out by 3-mercapto-1,2,4-triazole（MT）to obtain the MT/Cu electrode.This treatment aims to modify the lithiophilic molecular layer on the surface of the current collector copper foil to construct a liphophilic support.By electrochemically loading lithium,a lithium-prophilic-conductive carrier-lithium metal composite anode Li/MT/Cu with a uniform lithium deposition layer on the surface is finally obtained.This copper foil modified by MT molecule has good lipolyphilicity,and the copper foil substrate has excellent electrical conductivity.It has a positive effect on uniform electric field distribution and lithium flux,realizes uniform deposition of lithium,and has better cycling performance.Li/MT/Cu||Li/MT/Cu symmetric batteries can be stable for a long time in the long circulating cycle,with a lower overpotential stable circulation 600 h,and will not appear obvious potential problems such as increased polarization.The current density of lithium iron phosphate（LFP）and Li/MT/Cu electrode assembly can be stable for 200 cycles at 1C,and the capacity retention rate is high.And the preparation of electrodes is relatively simple,which is expected to become a competitor in the field of energy storage in the future.（2）Cu_xO nanowire arrays were grown in situ on three-dimensional current collector copper nets,and three-dimensional lithium metal carriers were constructed,which were applied to lithium metal anodes to improve the growth and instability of lithium metal anode dendrites.In the third chapter,3-mercapto-1,2,4-triazole（MT）was used to modify the surface monolayer self-assembly（SAM）of two-dimensional copper foil current collectors.However,the two-dimensional current collector cannot accommodate a large lithium deposition capacity due to its own planar characteristics,and cannot meet the needs of large-capacity lithium deposition.In order to solve the above problems,in Chapter 4,a three-dimensional lithiophilic carrier with Cu O/Cu₂O nanowire array（Cu_xO NW）grown in situ on a three-dimensional copper mesh substrate is designed and loaded with lithium metal to form a composite anode（Cu_xO NW@Li）.The three-dimensional Cu_xO NW lithiophilic carrier structure design allows it to provide higher lithium deposition capacity,lithiphilicity and specific surface area,thereby obtaining excellent electrochemical stability.Since lithium metal forms Li₂O in situ with Cu_xO NW,Cu²⁺and Cu¹⁺are reduced.Compared with pure Cu O nanowires,the introduction of Cu₂O makes the composite anode have a higher copper content,making it have better conductivity.Moreover,the three-dimensional structure can deposit a larger capacity of lithium metal to inhibit the expansion of lithium metal,and the symmetrical battery can be stably cycled for 1500h in a long cycle.This simple method provides a feasible strategy to achieve stable lithium deposition and high-performance lithium metal anodes.