Light‐Motivated SnO₂/TiO₂ Heterojunctions Enabling the Breakthrough in Energy Density for Lithium‐Ion Batteries

Abstract

Powering lithium‐ion batteries (LIBs) by light‐irradiation will bring a paradigm shift in energy‐storage technologies. Herein, a photoaccelerated rechargeable LIB employing SnO2/TiO2 heterojunction nanoarrays as a multifunctional anode is developed. The electron–hole pairs generated by the LixTiO2 (x ≥ 0) under light irradiation synergistically enhance the lithiation kinetics and electrochemical reversibility of both SnO2 and TiO2. Specifically, the electrons can quickly pour into the SnO2 and the generated Sn due to the more positive conduction band potentials (vs TiO2), and mean while the holes also promote the intercalation of Li+ into TiO2 by reaching charge balance. A remarkable increase in areal specific capacity is therefore achieved from 1.91 to 3.47 mAh cm−2 at 5 mA cm−2. More impressively, there is no capacity loss even through 100 cycles, which is the best report for photorechargeable LIBs to date, owing to the strong and stable photoresponse current. This finding exhibits a feasible pathway to break the limitation in the energy density of LIBs by the efficient conversion and storage of solar energy.

Photoelectrochemical energy storage materials: design principles and functional devices towards direct solar to electrochemical energy storage

“…The remaining holes in turn enhanced the Li + migration to the TiO 2 by achieving charge balance. 34…”

Integrated Photovoltaic Charging and Energy Storage Systems: Mechanism, Optimization, and Future

“…[ 145 ] On this basis, in view of the synergistic enhancement of the lithiation kinetics and electrochemical reversibility of tin oxide and titania by electron–hole pairs under illumination, Hu et al Photoaccelerated rechargeable lithium‐ion batteries with multifunctional anodes (Figure 10c). [ 1 ] The integrated multifunctional electrode achieves a significant increase in area specific capacity from 1.91 to 3.47 mAh at 5 mA cm −2 , and excellent performance without capacity loss for over 100 cycles (Figure 10d). [ 1 ]…”

“…[ 1 ] The integrated multifunctional electrode achieves a significant increase in area specific capacity from 1.91 to 3.47 mAh at 5 mA cm −2 , and excellent performance without capacity loss for over 100 cycles (Figure 10d). [ 1 ]…”

“…Reproduced with permission. [ 1 ] Copyright 2021, Wiley‐VCH. e) Structure of the three‐electrode photocapacitor.…”

A Facile Microwave Hydrothermal Method for Fabricating SnO2@C/Graphene Composite With Enhanced Lithium Ion Storage Properties

“…However, its applications in energy storage are limited due to the low-theoretical capacity (372 mAh g −1 ), considering the high energy density requirements from LIBs ( Chang et al, 2018 ; Liu et al, 2020 ). In order to meet the growing demand and expand the range of applications for high-performance LIBs, the development of advanced anode materials is crucial, such as Sn-based oxides ( Hu et al, 2021 ; Kuriganova et al, 2016 ; Das et al, 2016 ), Si-based oxides ( He et al, 2017 ; Xiang et al, 2017 ), Sb-based oxides ( Zhou et al, 2019 ), Fe-based oxides ( Li H. et al, 2021 ; Li et al, 2017 ), Co-based oxides ( Li Q. et al, 2021 ), Ti-based oxides ( Huang et al, 2018 ), transition metal sulfides ( Zhang et al, 2021 ; Xiao et al, 2021 ), and others ( Gao et al, 2020 ; Karahan et al, 2019 ), can provide their high theoretical lithium storage capacity and attract much attention.…”