Caging tin oxide in three-dimensional graphene networks for superior volumetric lithium storage

Abstract

Tin and its compounds hold promise for the development of high-capacity anode materials that could replace graphitic carbon used in current lithium-ion batteries. However, the introduced porosity in current electrode designs to buffer the volume changes of active materials during cycling does not afford high volumetric performance. Here, we show a strategy leveraging a sulfur sacrificial agent for controlled utility of void space in a tin oxide/graphene composite anode. In a typical synthesis using the capillary drying of graphene hydrogels, sulfur is employed with hard tin oxide nanoparticles inside the contraction hydrogels. The resultant graphene-caged tin oxide delivers an ultrahigh volumetric capacity of 2123 mAh cm–3 together with good cycling stability. Our results suggest not only a conversion-type composite anode that allows for good electrochemical characteristics, but also a general synthetic means to engineering the packing density of graphene nanosheets for high energy storage capabilities in small volumes.

FeCl3 Intercalated Microcrystalline Graphite Enables High Volumetric Capacity and Good Cycle Stability for Lithium‐Ion Batteries

“…To pursue the maximum energy in a limited space, the tap density of electrode materials has been described as an important indicator that reflects the volumetric energy density along with a lightweight packing in the battery industry. Unfortunately, the use of nanosized anodes with a high electrochemical performance will sacrifice the volumetric capacity because of the low tap density, making them still far from an acceptable level for the practical use …”

Engineering Graphenes from the Nano- to the Macroscale for Electrochemical Energy Storage

“…In a typical synthesis, flowable soft sulfur and hard SnO 2 nanoparticles grew together inside shrunken graphene hydrogels, and the void space around the SnO 2 particles was precisely controlled by tuning the content of the surrounding and removable sulfur. An ultrahigh volumetric capacity of 2123 mAh cm −3 together with good cyclic stability were achieved by packing the graphene network to a high density but with adequate void space for SnO 2 [116] (Fig. 11b-e).…”

“…13) [147]. Moreover, by embedding high-capacity non-carbon materials in the void space of the dense graphene matrix, the carbon-non-carbon hybrid delivered high volumetric capacitances even at a high mass loading of active materials and a high current density [83][84][85]116]. More importantly, the densification strategy makes the graphene-derived carbons promising in solving the use of other low-density nanocarbons in EES to increase energy density and power density.…”

“…e Cycling performance of SnO 2 @GC with different sulfur template usage. [116]. Copyright (2018) Nature Publishing group hybrid in which a graphene coating on the surface of sulfur particles helped trap the LiPSs and rendered the sulfur cathode highly conductive.…”

A Universal Strategy for Constructing Seamless Graphdiyne on Metal Oxides to Stabilize the Electrochemical Structure and Interface

“…It can be seen that the interfacial contact between the carbon components and MOs plays the critical role in integrating these advantages of all-carbon components and MOs. [1][2][3][4][5] In order to meet these Especially, the all-carbon modification would become more difficult in the case of MOs with complex dimensions and variations.…”