Robust and Fast‐Ion Conducting Interphase Empowering SiO_x Anode Toward High Energy Lithium–Ion Batteries

Abstract

Silicon suboxides (SiOx) materials are highly desirable as anode for high energy Li‐ion batteries due to their much higher specific capacity than conventional graphite anode. However, the low initial Coulombic efficiency (ICE) and inadequate capacity retention of SiOx anode arising from its immense volume variation during repeated lithiation/delithiation process greatly hinder its practical applications. To address these drawbacks of SiOx, by a simple calcination method, a robust and fast‐ion conducting interphase enriched of LiF, Li2C2O4, LiBO2, and Li2B4O7 is rationally pre‐constructed With the assistance of this pre‐constructed artificial protective layer, the formed solid‐electrolyte interphase (SEI) layer possesses high Young's modulus and fast Li+ conducting, and thus can accommodate the plastic deformation of SiOx anode, alleviate the parasitic reactions, and maintain the electrode integrity upon cycling. Thus, the modified SiOx (M‐SiOx) anode exhibits higher ICE, better capacity retention and superior rate capability. More encouragingly, full cells pairing the M‐SiOx anode with LiNi0.8Mn0.1Co0.1O2 cathode show a high capacity retention of 80.6% for 200 cycles. This paper reveals the importance of pre‐constructing an artificial SEI layer and regulating interfacial chemistry in improving the performance of SiOx‐based anodes, which is a milestone work for boosting the large scale application of SiOx‐based anodes.

Both Resilience and Adhesivity Define Solid Electrolyte Interphases for a High Performance Anode

“…These results demonstrate that the SiO x @C–CP anode possesses extraordinary cycling stability and fast electron/ion transport, which shows great competitiveness among reported Si-based anodes (Table S1). − This strategy is also effective in Si@C microparticles (3–5 μm) with larger volume fluctuation (∼300%) and also enables high-affinity encapsulation, improved cycling stability, and superior rate performance (Figures S9 and S10).…”

Interphase Regulation by Multifunctional Additive Empowering High Energy Lithium‐Ion Batteries with Enhanced Cycle Life and Thermal Safety

“…Li 2 F + ) in the SEI layer (Figure 3g, Figure S18), and LiF with excellent electrical insulation and high interfacial energy can effectively prevent continuous electrolyte reduction at low potentials and accommodate the large plastic deformation [2b–f,3,8,15] . Meanwhile, due to the enrichment of high mechanical strength LiF, the average Young's modulus of the cycled S650 anode is greatly increased by LiTFTCP additive [16] (Figure S19). As a result, the volume expansion of S650 anode (Figure 3h–i, Figure S20) are greatly alleviated by LiTFTCP additive.…”

“…Chemie and accommodate the large plastic deformation. [2b-f,3,8,15] Meanwhile, due to the enrichment of high mechanical strength LiF, the average Young's modulus of the cycled S650 anode is greatly increased by LiTFTCP additive [16] (Figure S19). As a result, the volume expansion of S650 anode (Figure 3h-i, Figure S20) are greatly alleviated by LiTFTCP additive.…”

In Situ Integration of a Flame Retardant Quasisolid Gel Polymer Electrolyte with a Si-Based Anode for High-Energy Li-Ion Batteries

“…To enhance the mechanical and electrochemical stability of silicon anodes, extensive investigations have been conducted in the following three aspects: (1) designs of silicon nanostructures, such as coating artificial SEI , or carbon buffer layers, building porous structures, and others; (2) use of effective binders for electrode integrity during the charge/discharge processes . Various polymer binders incorporating polar functional groups have been reported, such as poly­(acrylic acid) (PAA) containing −COOH and −OH, polyacrylamide (PAM), , and polyurethane (PU) with −CONH groups as well as others. − (3) The third is the use of compatible electrolytes.…”