Novel Strategy of Constructing Hollow Ga₂O₃@N-CQDs as a Self-Healing Anode Material for Lithium-Ion Batteries

Abstract

Self-healing materials arouse much attention because of their recoverable morphologies during (dis)charge. Herein, we report an effective and practical synthesis strategy that can adequately utilize the self-healing feature to achieve advanced integrative performance. The hollow Ga 2 O 3 @nitrogen-doped carbon quantum dot (H-Ga 2 O 3 @N-CQD) nanospheres are synthesized via a facile approach as an anode material for lithium-ion batteries (LIBs). In this anode, the self-healing capability is derived from the Ga generated in the conversion reaction. On account of the feasible structure design and the binding N-CQD coating, the material structure can be well preserved during (dis)charging. As a result, the anode material delivers an initial discharge capacity of 1348.5 mAh g −1 at 0.1 A g −1 and an invertible capacity of 700.5 mAh g −1 under 0.5 A g −1 after 500 cycles. Endowed by the unique structural design, the H-Ga 2 O 3 @N-CQDs can deliver high-current-density circulation performance and long-term cycle stability, which has prospects for large-scale applications in high-energy-density LIBs. Meanwhile, the rational framework design offers new insights into the structurebuilding construction of self-healing materials.

Scalable Synthesis of Ga2O3/N‐Doped C Nanopapers as High‐Rate Performance Anode for Li‐Ion Batteries

“…As show in Figure 4a, both C and Ga 2 O 3 /NC NPs electrodes show main redox peaks in voltage region 0–2 V, suggesting excellent electrochemical compatibility between Ga 2 O 3 and C. As seen, pristine C shows a reduction peak in 1–0 V region in cathodic scan and two oxidation peaks near 0.1 and 1.25 V, which correspond to the intercalation of Li‐ions into C accompanied by the formation of solid electrolyte interface as well as the deintercalation of Li‐ions from C [27] . In contrast, the Ga 2 O 3 /NC NPs electrode shows extra reduction peak near 0.25 V and oxidation peak near 0.78 V from the 2 nd curve afterward, indicating the reduction of Ga 2 O 3 into Ga and the formation of Li 2 Ga alloy as well as the release of Li‐ions from Li 2 Ga and the oxidation of Ga into Ga 2 O 3 [17,24,25] . The charge/discharge curves in Figure 4b coincide with the CV curves, and the main capacity contribution located in voltage region of 0–1.5 V. The pristine NC NPs delivers stable cycling at 0.2 A g −1 , showing charge/discharge capacity of 308/309 mAh g −1 after 200 cycles.…”

“…The rate performance of the Ga 2 O 3 /NC NPs‐1 is distinctly improved compared with previous study (Table 1). [8,15,17,23,24,46] …”

“…The unsatisfactory reaction kinetics of Ga 2 O 3 mainly correlate with: 1) the intrinsic high bandgap ( E g =4.9 eV) which seriously lowers the electron transfer in Ga 2 O 3 ; [19] 2) the morphology of Ga 2 O 3 is difficult to regulate, which results in modest Li‐ion diffusion [20–22] . To improve the electrochemical performance of Ga 2 O 3 , previous approach mainly focuses on integrating Ga 2 O 3 with various carbonaceous materials, such as amorphous carbon and graphene [15,17,23–25] . For example, Patel et al.…”

Recent progress in quantum dots based nanocomposite electrodes for rechargeable monovalent metal-ion and lithium metal batteries

“…Jiaqi Guo et al 164 demonstrated a microwave-assisted synthesis of N-CQDs and its decoration onto hollow Ga 2 O 3 nanospheres by a hydrothermal assisted self-assembly method. The constructed Ga 2 O 3 @N-CQD anode demonstrated self-healing behavior from Ga generated in the conversion reaction, where the N-doped CQD layers (∼10 nm in diameter) uphold the structural integrity and enhance the electronic conductivity.…”

A Microcapsule‐Assistant Self‐Healing Magnesium Battery Cathodes

“…[ 16–21 ] Introducing self‐healing materials into rechargeable batteries to enhance the stability has become an interesting strategy. [ 22 ] For example, a quasisolid‐state healable Zn‐ δ ‐MnO 2 battery using a carboxylated polyurethane gel as the self‐healing electrolyte was reported. [ 23 ] The reversible hydrogen bonds in the self‐healing gel could recombine spontaneously.…”