A High‐Energy Li‐Ion Battery Using a Silicon‐Based Anode and a Nano‐Structured Layered Composite Cathode

Abstract

High capacity electrodes based on a Si composite anode and a layered composite oxide cathode, Ni‐rich Li[Ni0.75Co0.1Mn0.15]O2, are evaluated and combined to fabricate a high energy lithium ion battery. The Si composite anode, Si/C‐IWGS (internally wired with graphene sheets), is prepared by a scalable sol–gel process. The Si/C‐IWGS anode delivers a high capacity of >800 mAh g−1 with an excellent cycling stability of up to 200 cycles, mainly due to the small amount of graphene (∼6 wt%). The cathode (Li[Ni0.75Co0.1Mn0.15]O2) is structurally optimized (Ni‐rich core and a Ni‐depleted shell with a continuous concentration gradient between the core and shell, i.e., a full concentration gradient, FCG, cathode) so as to deliver a high capacity (>200 mAh g−1) with excellent stability at high voltage (∼4.3 V). A novel lithium ion battery system based on the Si/C‐IWGS anode and FCG cathode successfully demonstrates a high energy density (240 Wh kg−1 at least) as well as an unprecedented excellent cycling stability of up to 750 cycles between 2.7 and 4.2 V at 1C. As a result, the novel battery system is an attractive candidate for energy storage applications demanding a high energy density and long cycle life.

Critical Insight into the Relentless Progression Toward Graphene and Graphene‐Containing Materials for Lithium‐Ion Battery Anodes

“…K. Sun et al [ 393 ] also reported a full-cell comprising a Nirich Li[Ni 0.75 Co 0.1 Mn 0.15 ]O 2 cathode and a pre-lithiated RGO/ Si hybrid anode (with a graphene content of about 6 wt%) ( Table 3 ). The cell, operating in the potential range 2.7-4.2 V, exhibited fi rst charge and discharge capacities of 206 and 196 mAh g −1 (at a current of 20 mA g −1 , based on the weight of cathode active material), respectively, yielding a Coulombic effi ciency of 95%.…”

Layered Oxide, Graphite and Silicon-Graphite Electrodes for Lithium-Ion Cells: Effect of Electrolyte Composition and Cycling Windows

“…We present the effect of electrolyte composition, by adding various amounts of VC and FEC to our baseline electrolyte; such reports on electrolyte composition effects on silicon-containing full cells are still relatively few. 18,[21][22][23][24][25][26] We also describe the effect of voltage windows on cell performance and durability. We remind the reader that the effect of voltage windows on cell cycle life is intrinsically related to the negative and positive electrode's capacity matching (n:p ratio), and to the initial coulombic efficiency, which together dictate the electrode potential limits within a cell.…”

Stable silicon-ionic liquid interface for next-generation lithium-ion batteries

“…In spite of these efforts, the CEs achieved throughout cycling are still insufficient for a long-lasting Si-based full-cell 31,[33][34][35] or the methods employed to manufacture the full-cells introduce large excesses of Li þ (4200%) into the system that serve to counterbalance the cell efficiency losses over long-term cycling [36][37][38] . In the effort to design next-generation electrolyte materials, room temperature ionic liquids (RTILs or ILs) are of particular interest due to their low volatilities, negligible vapour pressures, thermal stabilities, high-voltage stability windows and sufficient ionic conductivities 39 .…”