Wang Wankai, Yang Yanfei, Yang Jie, Zhang Junping
Key Laboratory of Clay Mineral of Gansu and Research Center of Resource Chemistry and Energy Materials, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, 730000, Lanzhou, P. R. China.
Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, 100049, Beijing, P. R. China.
Angew Chem Int Ed Engl. 2024 Aug 19;63(34):e202400091. doi: 10.1002/anie.202400091. Epub 2024 May 27.
Poly(ethylene oxide) (PEO)-based composite solid electrolytes (CSEs) are promising to accelerate commercialization of solid-state lithium metal batteries (SSLMBs). Nonetheless, this is hindered by the CSEs' limited ion conductivity at room temperature. Here, we propose design, synthesis, and application of the bioinspired neuron-like nanofillers for PEO-based CSEs. The neuron-like superhydrophobic nanofillers are synthesized by controllably grafting silicone nanofilaments onto montmorillonite nanosheets. Compared to various reported fillers, the nanofillers can greatly improve ionic conductivity (4.9×10 S cm, 30 °C), Li transference number (0.63), oxidation stability (5.3 V) and mechanical properties of the PEO-based CSEs because of the following facts. The distinctive neuron-like structure and the resulting synaptic-like connections establish numerous long-distance continuous channels over various directions in the PEO-based CSEs for fast and uniform Li transport. Consequently, the assembled SSLMBs with the CSEs and LiFePO or NCM811 cathodes display superior cycling stability over a wide temperature range of 50 °C to 0 °C. Surprisingly, the pouch batteries with the large-scale prepared CSEs kept working after being repeatedly bent, folded, cut or even punched in air. We believe that design of neuron-like nanofillers is a viable approach to produce CSEs with high room temperature ionic conductivity for SSLMBs.
基于聚环氧乙烷（PEO）的复合固体电解质（CSEs）有望加速固态锂金属电池（SSLMBs）的商业化进程。尽管如此，CSEs在室温下有限的离子电导率阻碍了这一进程。在此，我们提出了用于基于PEO的CSEs的仿生神经元状纳米填料的设计、合成及应用。通过将有机硅纳米丝可控地接枝到蒙脱石纳米片上合成了神经元状超疏水纳米填料。与各种已报道的填料相比，这种纳米填料能够极大地提高基于PEO的CSEs的离子电导率（4.9×10⁻⁴ S cm⁻¹，30 °C）、锂迁移数（0.63）、氧化稳定性（5.3 V）和机械性能，原因如下。独特的神经元状结构以及由此产生的突触状连接在基于PEO的CSEs中沿各个方向建立了众多长距离连续通道，以实现快速且均匀的锂传输。因此，由CSEs与LiFePO₄或NCM811阴极组装而成的SSLMBs在50 °C至0 °C的宽温度范围内显示出优异的循环稳定性。令人惊讶的是，采用大规模制备的CSEs制成的软包电池在空气中反复弯曲、折叠、切割甚至穿刺后仍能继续工作。我们认为，设计神经元状纳米填料是一种可行的方法，可为SSLMBs制备具有高室温离子电导率的CSEs。
