On the Interface Design of Si and Multilayer Graphene for a High-Performance Li-Ion Battery Anode

Abstract

Si/multilayer graphene (mG) is a promising candidate for the next-generation Li-ion battery anode. The highly ordered mG shows intrinsic good stability against the liquid electrolyte and its flexibility to accommodate volume change. Until now, reducing the growth temperature and thus engineering the interphase are a very important research area, but only few studies have been reported. Herein, for the first time, the mG is grown with the Al 2 O 3 catalyst at a relatively low temperature of 750 °C, while the thickness is controlled to 2 nm. The growth of mG obeys the Stranski− Krastanov mechanism. Applying a rapid cooling process, a silicon oxycarbide (SiOC) interlayer is in situ-fabricated between the mG coating layer and Si core. The SiOC interlayer is demonstrated to accommodate the volume change of Si and enable faster lithium ion transportation than mG. Taking synergetic advantages of the mG coating layer and SiOC interphase, the cycling stability significantly improved, and a high specific capacity of 990 mA h/g is obtained at 1 A/g after 500 cycles in half cells. A high rate performance of 1164.5 mA h/g at 4 A/g is achieved. Tested in a 1.8 A h pouch cell with LiNi 0.5 Mn 0.3 Co 0.2 O 2 (NMC532) as the cathode, the cell delivers a specific energy of ∼380 W h/kg. The capacity retentions are 93% and 78% after 100 cycles and 200 cycles, respectively. Our work highlights the importance of the interphase design of Si/mG composite anodes, which could also be extended to various core−shell materials in energy storage materials.

Gradient H‐Bonding Binder Enables Stable High‐Areal‐Capacity Si‐Based Anodes in Pouch Cells

“…Furthermore, we compared the lifetime and binder content of pouch cells with Si‐based composite as anodes in recent studies (details refer to Figure 4e). [ 55–60 ] Noticeably, the pouch cell with low‐content PAHT binder exhibits more remarkably cycling performances than those of previous reports. As demonstrated above, the PAHT binder contributes to improving the electrochemical properties of both Si and Si‐C anodes, showing a tremendous potential towards practical application.…”

“…e) Comparison of the lifespans and binder contents of the pouch cells reported in the literature. [ 55–60 ] The battery in this work shows an outstanding cycliability at a low binder content of 4.2 wt%. f) Cycling performance of the NCM/Si‐C full pouch cell at 1C between 2.75 and 4.2 V.…”

“…Based on the effect of PAHT binder on Si-C half cell, the pouch cell (Figure 4c) with commercial LiNi 0.5 Co 0.2 Mn 0.3 O 2 (NCM) as cathode were fabricated to further explore the [55][56][57][58][59][60] The battery in this work shows an outstanding cycliability at a low binder content of 4.2 wt%. f) Cycling performance of the NCM/Si-C full pouch cell at 1C between 2.75 and 4.2 V.…”

Nanostructured Graphene Oxide-Based Hybrids as Anodes for Lithium-Ion Batteries

“…Si/multilayer graphene (thickness controlled to 2 nm) delivered a capacity of 990 mAh g −1 at 1 A g −1 after 500 cycles. At 4 A g −1 , the capacity was 1164.5 mAh g −1 [99]. This result was attributed to the formation of a silicon oxycarbide interlayer formed by a rapid cooling during the synthesis process of the composite.…”

Synthesis of Si/Fe2O3-Anchored rGO Frameworks as High-Performance Anodes for Li-Ion Batteries

“…Table 1 displays the electrochemical performance of different Si-based electrode materials [26,28,[64][65][66][67][68][69][70]. The as-synthesized BM-SFG anode presents relatively excellent Li storage performance, which is better than that of many reported Si-based composites.…”