Cobalt Oxide Nanocubes Encapsulated in Graphene Aerogel as Integrated Anodes for Lithium‐Ion Batteries

Abstract

The development of metal oxides as anodes of lithium‐ion batteries is severely limited because of their poor conductivity and serious volume expansion during the cycles. This work focuses on the improvement of electronic conductivity and cycle stability of metal oxides. The nanocubes of Prussian blue analogues are firstly encapsulated in the network of graphene aerogel (GA), and then the Co3O4@GA composites are synthesized after the subsequent calcination treatment. The resulting products are used as free‐standing and high‐performance anodes of LIBs, and the optimal electrode delivers a specific capacity of 624 mAh g−1 at 100 mA g−1 after 100 cycles together with a good cycle stability. The extraordinary lithium‐storage performances can be ascribed to the synergistic interaction between metal oxides and GA substrate. The incorporation of GA improves the electrode conductivity and alleviates the aggregation and volume expansion of metal oxide particles upon cycling, whereas cobalt oxides contribute a high specific capacity.

Graphene Aerogel Supported Fe−Co Selenide Nanocubes as Binder‐Free Anodes for Lithium‐Ion Batteries

“…The CV curve of the first cycle is different from those of the subsequent two cycles especially for the discharge plot. In the first cycle, the strong peak at 1.2 V is related to the reduction of FeCoSe 2 to metallic state and the formation of Li 2 O [40] . The anodic peak at 2.2 V in the first lap is attributed to the oxidation reaction between Fe and Co species [41] .…”

Interlaced CoOx Nanosheets Composited with Reduced Graphene Oxide and Carbonized Bacterial Cellulose as Anode Materials for Lithium‐ion Batteries

“…To illustrate the excellent performance of GN/CoO x /CBC materials in this paper, the performance data of some material electrodes reported in recent years are compared (Table 1). [23–31] It is obvious that the GN/CoO x /CBC material has a good capacity, demonstrating that the GN/CoO x /CBC have a unique three‐dimensional nanofibrous conductive network and two‐dimensional “flexible confinement” function. The better rate performance is attributed to the unique hybrid structure, which creates larger space and leads to a large electrode‐electrolyte interfacial area.…”

“…To illustrate the excellent performance of GN/CoO x /CBC materials in this paper, the performance data of some material electrodes reported in recent years are compared (Table 1). [23][24][25][26][27][28][29][30][31] It is obvious that the GN/CoO x /CBC material has a good capacity, demonstrating that the GN/CoO x / CBC have a unique three-dimensional nanofibrous conductive network and two-dimensional "flexible confinement" function.…”

Carboxyl Function Group Introduced to Polyimide Binders for Silicon Anode Materials

“…To meet the ever increasing demands of portable electronics requirement for higher energy and power densities, high-performance materials development is imperative for lithium-ion batteries (LIBs). Silicon anode materials show the brightest future owing to their super high theoretical capacity (4200 mAh g –1 for Li 22 Si 5 ), − relatively low discharge potential (∼0.4 V versus Li + /Li), − and rich abundance in the earth. − Nevertheless, the commercial application of silicon anode materials is still hindered with the challenges related to the huge volume expansion. − The solid electrolyte interface (SEI) and electrode structure are damaged due to tremendous volume change of silicon anode materials during Li + lithiation and delithiation processes, which seriously deteriorate the lifespan of the lithium-ion battery. − Various strategies have been adopted to ameliorate these issues, such as controlling the morphology of silicon anode materials, − using late-model electrode structures, − and employing high-performance binders. − …”