西南科技大学宋英泽团队报道了通过甘油激活颗粒重建策略直接再生工业磷酸铁黑质。相关研究成果发表在2024年11月18日出版的国际学术期刊《德国应用化学》。

随着电动汽车销量的增加，未来几年内，大量用LiFePO₄（LFP）阴极组装的废旧锂离子电池（LIBs）将退役，这对其有效和环保的回收利用构成了重大挑战。废旧LFP阴极不能再利用的主要原因在于锂损失引起的晶格缺陷和应力累积引起的结构缺陷。

该文中，研究人员提出了一种原位颗粒重建策略，在工业环境中使用甘油直接再生废LFP黑质（S-BM）。甘油中丰富的羟基作为电子供体，有助于还原Fe（III）和修复Fe-Li反位缺陷（FeLi）。

甘油的螯合性能会干扰结构分解的颗粒，抑制奥斯瓦尔德熟化效应，促进晶界结合，产生晶粒尺寸均匀的层状微晶，在简单的退火过程后恢复其形态和晶体结构。

此外，再生的LFP恢复了Fe-O键，进一步抑制了结构畸变，改善了Li⁺迁移动力学。因此，再生的工业LFP黑质（R-BM）表现出优异的锂存储性能，在5C下循环500次后，放电容量为123.2 mA h g^–1（容量保持率为93.1%）。

附：英文原文

Title: Direct Regeneration of Industrial LiFePO4 Black Mass Through A Glycerol-Enabled Granule Reconstruction Strategy

Author: Chengzhi Feng, Yang Cao, Lixian Song, Bo Zhao, Qin Yang, Yaping Zhang, Xijun Wei, Guangmin Zhou, Yingze Song

Issue&Volume: 2024-11-18

Abstract: With the increasing sales of electric vehicles, lots of spent lithium-ion batteries (LIBs) assembled with LiFePO4 (LFP) cathodes will retire in the next few years, posing a significant challenge for their effective and environmentally-friendly recycling. The main reason why spent LFP cathodes fail to re-utilize lies in the lattice defects caused by lithium loss and structural defects resulting from stress accumulation. In this work, we propose an in-situ granule reconstruction strategy to directly regenerate spent LFP black mass (S-BM) using glycerol in industry settings. The hydroxyl groups abundant in glycerol serves as electron donor that help reduce Fe (III) and repair Fe–Li antisite defects (FeLi). Additionally, the chelating properties of glycerol intervene with structurally disintegrated particles, inhibiting Oswald ripening effect and promoting bonding of grain boundaries to generate lamellar microcrystals with homogeneous grain size, recover their morphology and crystal structure after a facile annealing procedure. Furthermore, the regenerated LFP restores Fe–O bonds which further inhibits structural distortion and improve Li+ migration kinetics. As a result, the regenerated industrial LFP black mass (R-BM) exhibits superior lithium storage performance with a discharge capacity of 123.2 mA h g–1 after 500 cycles at 5.0 C (a capacity retention rate of 93.1%).

DOI: 10.1002/anie.202418198

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202418198