Sudhakaran Ramadoss, Murugan Arumugam Vadivel
Advanced Functional Nanomaterials Research Laboratory, Centre for Nanoscience and Technology, Madanjeet School of Green Energy Technologies, Pondicherry University (A Central University), Dr. R. Venkataraman Nagar, Kalapet, Puducherry 605014, India.
ACS Appl Mater Interfaces. 2025 Jan 8;17(1):2498-2512. doi: 10.1021/acsami.4c16932. Epub 2024 Dec 26.
The development of quasi-solid-state lithium metal batteries (QSSLMBs) is hindered by inadequate interfacial contact, poor wettability between electrodes and quasi-solid-state electrolytes, and significant volume changes during long-term cycling, leading to safety risks and cataclysmic failures. Here, we report an innovative approach to enhance interfacial properties through the construction of QSSLMBs. A multilayer design integrates a microwave-synthesized LiAlTi(PO) (LATP) ceramic electrolyte, which is surface-coated with a lithiophilic conductive ink comprising VS and disulfonated functionalized graphene nanosheets (VS-DSGNS) using a low-cost nail-polish binder. Subsequently, a few drops of LiPF in EC/DMC liquid electrolyte (LE) are impregnated into the uncoated side of the LATP surface. The quasi-solid-state electrolyte pellet of LATP-VS-DSGNS surface was allowed to be in contact with the molten Li and held until Li flowed into the LATP-VS-DSGNS surface completely a "melt-infusion strategy" as an anode side. Additionally, a heterogeneous polymer matrix consisting of poly(ethylene oxide) (PEO) and poly(vinylidene difluoride) (PVDF) as a polymer interlayer is fabricated using a solution casting technique for improving the wettability between the LE impregnated side of LATP and cathode, to enhance overall charge transfer kinetics. The assembled symmetric cells, Li||LATP-VS-DSGNS||Li and Li||PEO-PVDF/LE-LATP||Li, demonstrate high lithium-ion conductivities of 3.69 × 10 and 1.02 × 10 S cm, respectively, with impressive lithium-ion transfer numbers of 0.84 and 0.93 at 25 °C. Both cells exhibit a highly reversible lithium stripping/plating cycling process for over 600 h, with minimal voltage polarization of 10 and 31.6 mV, across a broad redox window (-1 to 6 V), effectively inhibiting lithium dendrite formation. Furthermore, the combination of a surface-modified AlO dry-coated, high-nickel NMC622 cathode with the PEO-PVDF|LATP-VS-DSGNS||Molten-Li architecture in a CR2032 coin-type full-cell delivers a galvanostatic discharge capacity of 130.6 mAh g at a 1C rate after 200 cycles, achieving 84.3% capacity retention, thereby demonstrating substantial reduction in interfacial resistance and enhanced stable battery performance of QSSLMBs.
准固态锂金属电池（QSSLMBs）的发展受到界面接触不足、电极与准固态电解质之间润湿性差以及长期循环过程中显著的体积变化的阻碍，从而导致安全风险和灾难性故障。在此，我们报告一种通过构建QSSLMBs来增强界面性能的创新方法。一种多层设计集成了微波合成的LiAlTi(PO)（LATP）陶瓷电解质，其表面使用低成本的指甲油粘合剂涂覆有包含VS和二磺化功能化石墨烯纳米片（VS-DSGNS）的亲锂导电油墨。随后，将几滴LiPF在EC/DMC液体电解质（LE）中浸渍到LATP表面未涂覆的一侧。使LATP-VS-DSGNS表面的准固态电解质颗粒与熔融锂接触并保持，直到锂完全流入LATP-VS-DSGNS表面——一种作为阳极侧的“熔体注入策略”。此外，使用溶液浇铸技术制备了由聚环氧乙烷（PEO）和聚偏二氟乙烯（PVDF）组成的非均相聚合物基质作为聚合物中间层，以改善LATP浸渍LE的一侧与阴极之间的润湿性，从而增强整体电荷转移动力学。组装的对称电池Li||LATP-VS-DSGNS||Li和Li||PEO-PVDF/LE-LATP||Li在25°C下分别表现出3.69×10和1.02×10 S cm的高锂离子电导率，以及令人印象深刻的0.84和0.93的锂离子转移数。两个电池在超过600小时内都表现出高度可逆的锂剥离/电镀循环过程，在宽氧化还原窗口（-1至6 V）内的最小电压极化分别为10和31.6 mV，有效抑制了锂枝晶的形成。此外，在CR2032硬币型全电池中，表面改性的AlO干涂高镍NMC622阴极与PEO-PVDF|LATP-VS-DSGNS||Molten-Li结构相结合，在1C倍率下经过200次循环后提供130.6 mAh g的恒电流放电容量，实现了84.3%的容量保持率，从而证明了QSSLMBs的界面电阻大幅降低且电池性能稳定性增强。
