The　significant　volume　expansion　of　Si-based　electrodes　is　very　likely　to　lead　to　electrode　materials　exfoliation　at　the　interface　of　Cu　foil　current　collectors,　and　the　interfacial　stability　of　the　electrode　is　a　critical　issue　to　be　addressed　urgently.　Femtosecond　laser　ablating　is　an　advanced　surface　processing　technology,　which　can　produce　micro-nano　surface　structures　with　regular　patterns　and　significantly　improve　the　adhesive　strength.　In　this　paper,　a　green　femtosecond　laser　with　a　wavelength　of　515　nm　was　employed　to　deeply　ablate　and　texture　the　Cu　foils　(9　μm-thick),　and　the　effects　of　laser　energy　density　and　effective　pulse　number　on　the　surface　morphology　and　micro-nano　structure　of　Cu　foil　as　well　as　the　cycle　stability　of　Si-based　electrodes　of　Cu　foil　samples　with　different　structures　were　investigated.　A　femtosecond　laser　(TruMicro　5280　Femto　Edition,　TRUMPF)　equipped　with　a　scanning　galvanometer　(Scanlab　Hurry　SCAN14)　was　employed　to　deeply　ablate　the　groove　structure　on　the　Cu　foil　surface.　The　univariate　method　was　adopted.　Firstly,　the　effective　pulse　number　was　fixed　at　5,　and　the　laser　energy　density　was　1.27,　1.91,　2.55,　3.18,　3.82,　6.37　J/cm2,　respectively.　Then　the　laser　energy　density　was　fixed　at　3.18　J/cm2,　and　the　effective　pulse　number　was　5,　25,　50,　75,　respectively.　Based　on　the　results,　Cu　foils　with　different　groove　densities　and　groove　depths　were　designed.　The　surface　morphology　of　Cu　foil　was　observed　with　a　scanning　electron　microscope　(HITACHI　S-3400N)　and　a　super-depth-of-field　microscope　(KEYENCE　VHX-950F).　The　elemental　content　of　the　Cu　foil　surface　was　characterized　with　an　energy　spectrometer.　The　active　material　layer　was　formulated　and　coated　on　the　surface　of　the　Cu　foil　current　collector.　The　active　material　layer　was　composed　of　70%　of　active　material　Si　(100　nm　in　diameter),　20%　of　binder　and　10%　of　conductive　agent.　The　electrodes　(active　layers　and　current　collectors)　were　dried　for　8　h　at　80　℃　under　vacuum　before　they　were　transferred　into　the　glove　box　for　cell　assembly.　The　cells　were　tested　by　galvanostatic　cycling　at　1C　rate.　It　was　found　that　the　ablation　threshold　of　the　green　femtosecond　laser　of　Cu　foil　was　0.52　J/cm2,　and　the　width　of　the　ablated　area　increased　gradually　with　the　laser　energy　density.　But　when　the　laser　energy　density　was　too　high,　the　ablating　effect　appeared　＇saturation＇　phenomenon.　The　surface　of　the　ablated　groove　was　nanostructured　and　no　significant　oxidation　occurred.　The　optimal　laser　energy　density　for　deeply　etching　was　3.18　J/cm2,　and　the　depth　of　the　groove　could　be　regulated　by　changing　the　effective　pulses　number.　The　cycle　stability　of　the　Si-based　electrodes　gradually　increased　with　the　increase　of　groove　density　and　depth.　It　was　worth　noting　that　when　the　groove　density　was　75%　and　the　groove　depth　was　6　μm,　the　capacity　remained　911　mA·h/g　after　300　cycles　at　1C　with　a　retention　rate　of　89%.　Using　femtosecond　laser　deep　ablation　method　and　optimizing　the　laser　parameters　can　successfully　prepare　micron-groove　structure　on　the　surface　of　Cu　foil.　The　nanostructure　increases　the　adhesive　strength　between　the　electrode　and　the　current　collector,　while　the　micro-groove　structure　protects　the　electrode　and　alleviates　its　volume　expansion.　The　deeply　ablated　Cu　foil　significantly　improves　the　exfoliation　of　the　Si-based　electrodes　and　achieves　the　enhancement　of　the　electrochemical　performance.　©　2024　Chongqing　Wujiu　Periodicals　Press.　All　rights　reserved.