Silicon–carbon (Si/C) anodes have emerged as promising alternatives to conventional graphite anodes for high-energy lithium-ion batteries (LIBs), owing to their higher specific capacity than graphite and enhanced cycling stability over pure silicon. However, the unstable solid electrolyte interphase (SEI) due to large volume changes during cycling is still a key bottleneck limiting their electrochemical performance. To address this critical limitation, the present study introduces wheat gluten (WG), a biomass-derived material from wheat, as a low-cost and sustainable binder for Si/C anodes. WG, rich in organic functional groups such as −COOH and −NH2, exhibits unique coordination capabilities with Li+. When employed as a binder, WG effectively induces the formation of Li+ solvated structures that weaken solvent coordination at the electrode surface/interface. This behavior facilitates the preferential growth of a LiF-rich SEI, thereby enhancing interfacial stability and mitigating capacity fade. Consequently, Si/C anodes employing WG binder (Si/C-WG) demonstrate remarkable cycling performance, delivering 95.9% capacity retention after 300 cycles at 0.5 A g–1, far surpassing that of conventional poly(vinylidene difluoride) (PVDF) binder, which retains only 59.5%. This study presents a novel strategy for designing functional binders optimized for Si/C anodes, offering critical insights to advance the development of high-performance anode materials in LIBs.
Haifeng Tu,Linge Li,Zhicheng Wang,Jian Wang,Hongzhen Lin,Mingchao Wang,Cheng Yan,Meinan Liu
A solid electrolyte interphase (SEI) with robust mechanical property and high ionic conductivity is imperative for high-performance lithium metal batteries since it can efficiently impede the growth of notorious lithium dendrites. However, it is difficult to form such a SEI directly from an electrolyte. In this work, a crowding dilutant modified ionic liquid electrolyte (M-ILE) has been developed for this purpose. Simulations and experiments indicate that the 1,2-difluorobenzene (1,2-dfBen) dilutant not only creates a crowded electrolyte environment to promote the interaction of Li+–FSI–, leading to abundant aggregate ion pairs (AGGs), but also participates in the reduction to construct a robust and high ionic-conductive SEI. With this M-ILE, Li/LiFePO4 cells achieve a capacity retention of 96% over 250 cycles with 9.5 mg cm–2 mass loading, and Li/LiNi0.5Co0.2Mn0.3O2 cells also deliver a discharge capacity of 132 mAh g–1 with a high retention of 88% after 100 cycles. Therefore, the use of a crowding diluent is considered to be an efficient way to construct an advanced SEI for a Li anode.
Xiuling Dong,Xinyi Ge,Wei Chen,Shuangqing Li,Zheng Xing,Qingguo Zhang,Zhong-Xia Wang
The interface problem between Li anode and gel polymer electrolytes (GPEs) hinder the performance improvement and application of Li metal batteries (LMBs). Herein, a GPE showcasing high ionic conductivity (3.91 mS cm −1 ) and elastic modulus (6.04 MPa) as GPE based on poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) was devised by introducing ionic liquids (ILs). The reconfiguration of Li ion solvation environment and the formation of LiF-rich solid electrolyte interface (SEI) protective layer have improved the interface problem. The LMB assembled from an optimized GPE- ET0.25 has stable Li deposition and excellent electrochemical properties , making the Li||LiFePO 4 (LFP) battery attaining an impressive long-cycle capacity retention rate of 96.0 %. This study emphasizes the advantages of IL aligned GPEs design, and the significance of forming stable SEI to improve battery performance, and provides ideas for the design of flexible LMBs with high safety and high performance.
危险品化学品经营许可证（带存储）