Highly Porous Free-Standing rGO/SnO2 Pseudocapacitive Cathodes for High-Rate and Long-Cycling Al-Ion Batteries

Abstract

Establishing energy storage systems beyond conventional lithium ion batteries requires the development of novel types of electrode materials. Such materials should be capable of accommodating ion species other than Li+, and ideally, these ion species should be of multivalent nature, such as Al3+. Along this line, we introduce a highly porous aerogel cathode composed of reduced graphene oxide, which is loaded with nanostructured SnO2. This binder-free hybrid not only exhibits an outstanding mechanical performance, but also unites the pseudocapacity of the reduced graphene oxide and the electrochemical storage capacity of the SnO2 nanoplatelets. Moreover, the combination of both materials gives rise to additional intercalation sites at their interface, further contributing to the total capacity of up to 16 mAh cm−3 at a charging rate of 2 C. The high porosity (99.9%) of the hybrid and the synergy of its components yield a cathode material for high-rate (up to 20 C) aluminum ion batteries, which exhibit an excellent cycling stability over 10,000 tested cycles. The electrode design proposed here has a great potential to meet future energy and power density demands for advanced energy storage devices.

SnO2/Sn/Carbon nanohybrid lithium‐ion battery anode with high reversible capacity and excellent cyclic stability

“…Because of the high surface area of the SnO 2 /Sn/C, the progressive penetration of the electrolyte in the mesoporous structure and side reactions with the electrolyte during cycling results in the increasing capacities. [ 15,53 ] Figure 4C shows the cycling behavior of the SnO x /Sn/C (black), SnO x /Sn/SiO x /C (red), and SnO 2 /Sn/C (blue) nanohybrids at a current density of 200 mA g –1 . The initial charge capacities are 236, 690, and 1259 mAh g –1 for the SnO x /Sn/C, SnO x /Sn/SiO x /C, and SnO 2 /Sn/C respectively.…”

“…The increase of the capacities might be attributed to the activation of the mesoporous SnO 2 /Sn/C nanohybrids and subsequent reduction with the electrolyte. [ 15,53 ]…”

“…[ 3–6 ] Tin‐based LIB anode materials have been explored because of their high theoretical specific capacity and appropriate working potential during the lithiation and delithiation processes. [ 7–15 ] Nevertheless, the Sn‐based anode materials still suffer immense capacity fading due to large volume expansion (300%) in repeated charge and discharge processes. [ 12,16 ] The significant amount of research work has been reported to tackle this issue.…”

Nanostructured Materials for Energy Storage and Conversion

“…The ten articles published in this Special Issue showcase the different applications of nanomaterials in the field of energy storage and conversion, including electrodes for Li-ion batteries (LIBs) and beyond [1][2][3], photovoltaic materials [4][5][6], pyroelectric energy harvesting [7], and (photo)catalytic processes [8][9][10]. The scientific contributions are briefly summarized in the following.…”

“…Jahnke at al. studied a highly porous aerogel cathode composed of reduced graphene oxide (rGO), which is loaded with nanostructured SnO 2 that serves as a cathode material for high-rate Al-ion batteries [3]. This binder-free hybrid has excellent mechanical properties and combines the pseudocapacity of rGO with the electrochemical capacity of SnO 2 nanoplatelets.…”