近日，中国科学技术大学季恒星团队实现了Nano-Bi@Hard用于385 Wh^-1体积能量密度和耐久性钠离子电池的碳复合阳极。2025年8月4日，该成果发表在《美国化学会志》上。

钠离子电池（SIB）是锂离子电池（LIB）在可持续能源存储方面的有前途的替代品，但其在紧凑型应用中的应用受到低体积能量密度（VED）或相对较差的结构不稳定性的阻碍。

研究组提出了一种nano-Bi@hard碳（nano-Bi@HC）复合材料，其特点是将均匀分散的Bi纳米颗粒（6-18 nm）密集排列的微球嵌入硬碳基体中，实现了385 Wh ^{- 1}的显著VED，具有出色的循环稳定性（在4000次循环中保持97%）。利用果胶的羧基官能团，Bi³⁺离子均匀配位，使炭化过程中铋含量高（86.2 wt %）而不团聚。nano-Bi@HC阳极在高面负载（12.3 mg cm^-2）和压实密度（4.8 g cm^-3）下具有无与伦比的1950 mAh cm^-3的体积容量。

与Na₃V(PO₄)₃阴极配对，整个电池在温度范围内表现出优异的性能，突出了其实用潜力。该研究建立了一种可扩展的策略，用于设计高VED和耐用的合金基阳极，弥合了SIB技术的关键空白。

附：英文原文

Title: Nano-Bi@Hard Carbon Composite Anode for Sodium-Ion Batteries with 385 Wh L–1 Volumetric Energy Density and Durability

Author: Zhiyu Lu, Haolei Yu, Yunhong Wei, Chengcheng Cao, Rong Liang, Guolei Cai, Song Jin, Hongchang Jin, Yong Ni, Yue Lin, Hengxing Ji

Issue&Volume: August 4, 2025

Abstract: Sodium-ion batteries (SIBs) are promising alternatives to lithium-ion batteries (LIBs) for sustainable energy storage, yet their adoption in compact applications is hindered by a low volumetric energy density (VED) or relatively poor structural instability. Herein, we present a nano-Bi@hard carbon (nano-Bi@HC) composite featuring densely packed microspheres with uniformly dispersed Bi nanoparticles (6–18 nm) embedded in a hard carbon matrix, achieving a remarkable VED of 385 Wh L–1, with exceptional cycling stability (97% retention over 4000 cycles). Utilizing pectin’s carboxyl functional groups, Bi3+ ions were homogeneously coordinated to enable a high Bi content (86.2 wt %) without agglomeration during carbonization. The nano-Bi@HC anode exhibits an unparalleled volumetric capacity of 1950 mAh cm–3 under a high areal loading (12.3 mg cm–2) and compaction density (4.8 g cm–3). Paired with a Na3V(PO4)3 cathode, the full cell demonstrates a superior performance across temperature ranges, highlighting its practical potential. This study establishes a scalable strategy for designing high-VED and durable alloy-based anodes, bridging critical gaps in SIB technology.

DOI: 10.1021/jacs.5c03507

Source: https://pubs.acs.org/doi/abs/10.1021/jacs.5c03507