Ma Qingtao, Sun Xiaowen, Liu Ping, Xia Yongyao, Liu Xingjiang, Luo Jiayan
Key Laboratory for Green Chemical Technology of Ministry of Education, State Key Laboratory of Chemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China.
Department of NanoEngineering, University of California San Diego, La Jolla, CA, 92093, USA.
Angew Chem Int Ed Engl. 2019 May 6;58(19):6200-6206. doi: 10.1002/anie.201900783. Epub 2019 Feb 20.
Progress in lithium-metal batteries is severely hindered by lithium dendrite growth. Lithium is soft with a mechanical modulus as low as that of polymers. Herein we suppress lithium dendrites by forming soft-hard organic-inorganic lamella reminiscent of the natural sea-shell material nacres. We use lithium as the soft segment and colloidal vermiculite sheets as the hard inorganic constituent. The vermiculite sheets are highly negatively charged so can absorb Li then be co-deposited with lithium, flattening the lithium growth which remains dendrite-free over hundreds of cycles. After Li ions absorbed on the vermiculite are transferred to the lithium substrate, the vermiculite sheets become negative charged again and move away from the substrate along the electric field, allowing them to absorb new Li and shuttling to and from the substrate. Long term cycling of full cells using the nacre-mimetic lithium-metal anodes is also demonstrated.
锂枝晶的生长严重阻碍了锂金属电池的发展。锂质地柔软，其机械模量与聚合物相当。在此，我们通过形成类似于天然贝壳材料珍珠层的软硬有机-无机薄片来抑制锂枝晶。我们将锂用作软段，将胶体蛭石片用作硬无机成分。蛭石片带有大量负电荷，因此可以吸收锂，然后与锂共沉积，使锂的生长变平，在数百次循环中都不会产生枝晶。在蛭石上吸收的锂离子转移到锂基底后，蛭石片再次带负电，并沿电场离开基底，从而使其能够吸收新的锂并在基底之间穿梭往返。还展示了使用仿珍珠层锂金属阳极的全电池的长期循环性能。
