Self-Healing Silicon Anode via the Addition of GaInSn-Encapsulated Microcapsules

Abstract

Silicon materials as promising anodes for lithium-ion batteries own a high specific capacity and a low discharge potential, while their application is restricted by their huge volumetric expansion and poor conductivity. In this study, a self-healing GaInSn–MS/Si hybrid electrode using an additive of microencapsulated gallium- liquid metal (GaInSn) with high electrical conductivity and mobility (LM microcapsule) was fabricated via an aqueous casting process. With the added LM microcapsule in the GaInSn–MS/Si hybrid electrode, the dispersed GaInSn could not only avoid its oxidation into a solid-state gallium oxide with decreased conductivity but also make it easy for uniform dispersion and quick fluidity. Consequently, the constructed self-healing GaInSn–MS/Si anode does not require manual splicing when the anode forms cracks, realizing a spontaneous self-healing performance, and the GaInSn–MS/Si hybrid electrode displays superior cycle stability and structural integrity, which retains a capacity of 806.7 mAh g–1 after 100 cycles at 2.1 A g–1. The constructed self-healing Si electrode structure design via LM microcapsule additives would provide a simple synthesis strategy for manufacturing advanced Si electrodes.

Bio‐Inspired Electrodes with Rational Spatiotemporal Management for Lithium‐Ion Batteries

“…[211] Furthermore, the element doping, surface coating, and optimization of the synthesis process in electrode materials enable to achieve significant electrochemical performance improvement on super high discharge capacity or capacity retention of LIBs. [100] Bio-inspired electrodes are developed with self-healing coreshell structure, [30][31][32][33][34][35] self-healing binders, [36][37][38][39][40] liquid metal alloys, [41][42][43][44][45][46] microcapsules, [48][49][50] and current collectors. [51] These electrodes owning self-healing capabilities possess much more stable mechanical characteristics than conventional electrode materials that can be shortened their durability by mechanical fractures generated during cycling.…”

“…LIBs comprise the cathode, anode, separator, current collector, electrolyte, and battery housing. [ 27 , 28 ] Their degradation can be minimized in smart electrodes via preventive steps, like artificial interfaces, [ 29 ] coatings, [ 30 , 31 , 32 , 33 , 34 , 35 ] self‐healing binders, [ 36 , 37 , 38 , 39 , 40 ] liquid metal alloys, [ 41 , 42 , 43 , 44 , 45 , 46 , 47 ] microcapsules, [ 48 , 49 , 50 ] and current collectors. [ 51 ] For instance, silicon (Si) anode severe volume expansion of up to 300% in the lithiation state leads to solid electrolyte interface (SEI) rupture, which decreases the electrochemical performance of LIB during cycling processes, and its lifetime become shortened.…”

“…Reproduced with permission. [ 48 ] Copyright 2022, ACS Applied Energy Materials. Reproduced with permission.…”

“…SEM images of b,c) the pure Si anode and e,f) 20% EGaInSn-MS/Si hybrid anode after 100 cycles. B) Cycling performance of the EGaInSn-MS/Si anode, pure EGaInSn/Si anode, and pure Si anode at 2.1 A g −1 a) and rate capability of the EGaInSn-MS/Si hybrid anode, pure EGaInSn/Si anode, and pure Si anode at 2.1, 4.2, and 8.4 A g −1 b) [48]. Copyright 2022, ACS Applied Energy Materials.…”

Study of the Electrochemical and Self-healing Processes of Galinstan as an Anode Material for Li-ion Batteries

“…5 Some groups have used Ga-In-Sn (galinstan) liquid alloy to form nano-composites made of nanoparticles of silicon and galinstan. [6][7][8][9] The liquid alloy is used to "heal" the cracking in the silicon electrode by filling the cracks due to its liquid nature and to ensure electrical contact of the electrode with the current collector. 8 Another application of galinstan is to use it as a liquid metal coating on current collectors to induce epitaxial lithium plating.…”