# Rational Design of 2D/3D Bi2O2Se–CNT Hybrid Architectures for Synergistic Lithium Storage

## TL;DR

This paper introduces a new hybrid material combining 2D Bi2O2Se with 3D carbon nanotubes to improve lithium storage in batteries, offering higher capacity and stability.

## Contribution

A novel structural engineering strategy using high-temperature calcination to create 2D/3D Bi2O2Se–CNT hybrid architectures for enhanced lithium storage.

## Key findings

- The Bi2O2Se–CNT-2 composite achieves an initial discharge capacity of 1544.7 mA h g−1 at 0.1 A g−1.
- It retains 74.8% of its capacity after 250 cycles and shows 35.2% capacity retention at 2 A g−1.
- The hybrid structure enables a combination of intercalation, conversion, and alloying reactions for lithium storage.

## Abstract

The development of advanced anode materials with high capacity and structural stability addressing the limitations of conventional graphite anodes in theoretical capacity (372 mA h g−1) and severe volume expansion remains a critical challenge for lithium-ion batteries (LIBs). Herein, we propose a structural engineering strategy through high-temperature calcination to construct 2D layered Bi2O2Se integrated with optimized 3D carbon nanotube (CNT) frameworks (Bi2O2Se–CNT-x). Comprehensive characterization (XRD, Raman, FESEM, XPS) verifies the high crystallinity of Bi2O2Se and the successful establishment of 3D conductive networks through interfacial coupling with CNTs. Electrochemical evaluation demonstrates that the optimized Bi2O2Se–CNT-2 composite delivers a remarkable initial discharge capacity of 1544.7 mA h g−1 at 0.1 A g−1, significantly outperforming pristine Bi2O2Se (124.3 mA h g−1). Notably, it maintains superior rate capability (405.0 mA h g−1 at 2 A g−1, 35.2% capacity retention) and cycling stability (74.8% capacity retention after 250 cycles), attributed to the synergistic effects between 2D Bi2O2Se lamellae and the conductive CNT matrix. The 3D CNT network facilitates rapid electron transport while mitigating volume fluctuations, whereas the layered Bi2O2Se enables a hybrid storage mechanism combining intercalation, conversion, and alloying reactions. This work broadens the application horizons of 2D layered materials in energy storage systems.