Dong Chenlong, Wang Ruiqi, Zhang Yuanxia, Fu Qiang, Zhao Siwei, Li Guobao, Mao Zhiyong, Huang Fuqiang
Tianjin Key Laboratory for Photoelectric Materials and Devices, School of Materials Science and Engineering, Tianjin University of Technology, Tianjin, 300384, P.R. China.
Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, P.R. China.
Angew Chem Int Ed Engl. 2025 Jun 18:e202508673. doi: 10.1002/anie.202508673.
High-energy lithium-ion batteries (LIBs) demand next-generation alloying-type anodes with high capacity and low voltage. While silicon-based anodes are in industrial use, commercial alloying-type anodes still suffer from excessive volume expansion and inadequate cycle life. Even incorporating silicon-carbon composites within graphite (typically <20% in commercial products) fails to resolve these limitations. Herein, we report a novel SrGeOS anode for ultralong-cycling lithium storage. An oxysulfide matrix (Li₂O/SrS) was in situ formed around Ge nanodomains. Enabled by the strong covalency of soft S⁻ anions and the pinning effect of large Sr⁺ ions, this synergistic matrix has demonstrated capabilities to enhance interfacial compatibility with Ge, facilitate efficient Li⁺ transport, suppress agglomeration of Ge nanoparticles and buffer volume expansion, as evidenced by in/ex situ characterizations, density functional theory calculations, and finite element analysis simulations. The anode harvests a low charging medium voltage of 0.42 V and reversible capacity of 587 mA h g at 0.1 A g after 800 cycles (8300 h) with 93.2% capacity retention. The LiCoO||SrGeOS full cell delivers a high capacity of 142 mA h g and energy density of 482 Wh kg. This work sheds light on constructing functional matrix to relieve volume expansion and particle agglomeration of high-capacity ultralong-cycling alloying-type anodes.
高能量锂离子电池（LIBs）需要具有高容量和低电压的下一代合金型负极。虽然硅基负极已投入工业使用，但商用合金型负极仍存在过度的体积膨胀和循环寿命不足的问题。即使在石墨中加入硅碳复合材料（在商业产品中通常<20%）也无法解决这些限制。在此，我们报道了一种用于超长循环锂存储的新型SrGeOS负极。在Ge纳米域周围原位形成了一种氧硫化物基体（Li₂O/SrS）。通过软S⁻阴离子的强共价性和大Sr⁺离子的钉扎效应，这种协同基体已证明能够增强与Ge的界面相容性、促进Li⁺的高效传输、抑制Ge纳米颗粒的团聚并缓冲体积膨胀，原位/非原位表征、密度泛函理论计算和有限元分析模拟都证明了这一点。该负极在0.1 A g下经过800次循环（8300小时）后，充电中电压低至0.42 V，可逆容量为587 mA h g⁻¹，容量保持率为93.2%。LiCoO₂||SrGeOS全电池具有142 mA h g⁻¹的高容量和482 Wh kg⁻¹的能量密度。这项工作为构建功能基体以缓解高容量超长循环合金型负极的体积膨胀和颗粒团聚提供了思路。
