Micro-nano Solid-state Battery Assembly And Mechanochemical Coupling Effect Research Based On SEM/TEM

With the continuous upgrading of military electronic devices to miniaturization and high frequency,integrated and miniaturized energy storage devices with small size and excellent electrochemical performance have become an indispensable part of microelectronic devices.However,there is an insurmountable gulf between microelectronics,which makes tiny devices,and electrochemistry,which makes batteries,due to differences in processing methods.Different processing methods lead to material incompatibility.Many high-performance battery materials cannot be easily processed on-chip and need to be fundam entally redesigned.Based on the nanomanipulation robotic system in the dual beam electron microscope,the bottom-up manufacturing process can be realized to process the prototype of the micro-nano battery;Based on the transmission electron microscope micro-nano operating system,the observation of the atomic-level structure evolution can be realized,and the dynamic tracking of the lithium ion transport channel at the surface interface during charging and discharging and the crystallographic analysis of the failure mechanism can be realized.This provides an effective research method for the fabrication,operation and assembly of micro-nano batteries.Based on the nano-manipulation robot system in the double beam electron microscope,the assembly method of Sb₂Se₃-Li micro-nano battery was studied,and the assembly experiment of Sb₂Se₃-Li micro-nano battery was carried out;Using the high-resolution transmission electron microscope and the imaging ability of the ultrafast CCD camera,we can understand the evolution law of the domain structure and phase structure during the intercalation/delithiation process from the sub-Angstrom scale,and reveal the physical nature of its dynamic behavior.The main research contents of this paper are as follows:（1）Assemble the micro-nano battery based on the nano-manipulation robot system in the electron microscope.Some subdivision tasks are involved in the assembly process.The Sb₂Se₃nanosheets are processed,cut,picked up,detected,positioned,and transferred.The electron/ion beam induced deposition method is used to fix the nanosheets on the surface of the metal electrode.The movable tungsten tip picks up lithium as the lithium source.The exposure time in air is controlled to generate a solid electrolyte.Corresponding operation strategies were designed for these tasks.Based on these strategies,Sb₂Se₃-Li_xO-Li micro-nano solid-state batteries were successfully assembled.（2）Based on this typical structure of the Sb₂Se₃-Li_xO-Li micro-nano solid-state battery,the reversible lithium-ion transport and the kinetic behavior of the reaction interface during the reaction of single crystal Sb₂Se₃ were directly observed by transmission electron microscopy.In situ dynamic tracking of lithium-ion intercalation and deintercalation channels,structural evolution and composition distribution in Sb₂Se₃-Li_xO-Li micro-nano solid-state batteries.The three-step reaction mechanism of insertion-conversion-alloying for Sb₂Se₃-Li_xO-Li micro-nano solid-state batteries was revealed.Lithiation proceeds sequentially through intercalation,transformation,and alloying reactions;delithiation causes the phase boundary to shrink,forming partially structurally intact single-crystal Sb₂Se₃.（3）In situ studies have found that the coupling effects of electrochemical reactions and mechanics have complex interactions at the atomic scale.A zigzag phase boundary with various types of defects was found between Li_xSb₂Se₃ and amorphous Li_xSb₂Se₃,including dislocation dipoles,antiphase boundaries,cracks,and failed Sb₂Se₃ nanodomains.The diffusion of Li ions leads to a significant accumulation of stress at the front-end interface,which can be relieved by the generation and movement of periodic dislocation dipole arrays.The stress that cannot be released in the future leads to the generation of cracks,and the crack evolution in turn promotes the diffusion of lithium-ion and accelerates the electrochemical intercalation reaction,resulting in the formation of failed Sb₂Se₃ nanodomains in the amorphous Li_xSb₂Se₃ matrix.