Kill two birds with one stone: Self-nanoparticlization β-Cu2Se anode enabled by high efficiency and low-cost synthesis for wide-temperature sodium-ion batteries

Abstract

The growing demand for electrochemical energy storage has accelerated the generation of battery waste, intensifying the need to recycle valuable components. However, transforming these discarded materials into high-rate electrode materials remains a significant challenge. Herein, we have proposed a unique strategy that converts waste copper foil into β-Cu 2 Se microparticles via a straightforward one-step solid-phase selenization process. When evaluated as an anode in a sodium half-cell, Cu 2 Se exhibits remarkable rate capability and cycling stability, achieving a capacity of 190 mAh g −1 within just 34 s, even at 20 A g −1 , and an impressive volumetric capacity of 1171 mAh cm −3 . Furthermore, a full sodium-ion battery incorporating the Cu 2 Se anode operates reliably across a wide temperature range (−20 to 40 ℃) in an ether-based electrolyte. This full battery also boasts exceptional rapid-charging capabilities, completing one cycle within only 5.3 min at −20 ℃. The distribution of relaxation times, in situ X-ray diffraction, and ex situ microscopy techniques reveal that the enhanced charge transfer and stabilized solid electrolyte interface film, which originated from the self-nanoparticlization, highly reversible structure, and dominant pseudocapacitive contribution, account for its outstanding capability. This work provides a novel strategy to tackle the challenge facing the regeneration of waste metals into high-value electrode materials. • The conversion of waste copper foil into β-Cu 2 Se microparticles is achieved via a one-step solid-phase selenization process. • The self-nanoparticlization behavior enhances charge transfer and stabilizes solid electrolyte interface. • The full battery exhibits impressive performance across a wide temperature range.

Topics & Concepts