Alexander George V, Shi Changmin, O'Neill Jon, Wachsman Eric D
Department of Materials Science and Engineering, University of Maryland, College Park, MD, USA.
Maryland Energy Innovation Institute, University of Maryland, College Park, MD, USA.
Nat Mater. 2023 Sep;22(9):1136-1143. doi: 10.1038/s41563-023-01627-9. Epub 2023 Aug 3.
The development of solid-state Li-metal batteries has been limited by the Li-metal plating and stripping rates and the tendency for dendrite shorts to form at commercially relevant current densities. To address this, we developed a single-phase mixed ion- and electron-conducting (MIEC) garnet with comparable Li-ion and electronic conductivities. We demonstrate that in a trilayer architecture with a porous MIEC framework supporting a thin, dense, garnet electrolyte, the critical current density can be increased to a previously unheard of 100 mA cm, with no dendrite-shorting. Additionally, we demonstrate that symmetric Li cells can be continuously cycled at a current density of 60 mA cm with a maximum per-cycle Li plating and stripping capacity of 30 mAh cm, which is 6× the capacity of state-of-the-art cathodes. Moreover, a cumulative Li plating capacity of 18.5 Ah cm was achieved with the MIEC/electrolyte/MIEC architecture, which if paired with a state-of-the-art cathode areal capacity of 5 mAh cm would yield a projected 3,700 cycles, significantly surpassing requirements for commercial electric vehicle battery lifetimes.
固态锂金属电池的发展受到锂金属电镀和剥离速率以及在商业相关电流密度下形成枝晶短路趋势的限制。为了解决这个问题，我们开发了一种具有可比锂离子和电子电导率的单相混合离子和电子传导（MIEC）石榴石。我们证明，在具有多孔MIEC框架支撑薄而致密的石榴石电解质的三层结构中，临界电流密度可以提高到前所未有的100 mA/cm²，且无枝晶短路。此外，我们证明对称锂电池可以在60 mA/cm²的电流密度下连续循环，每个循环的最大锂电镀和剥离容量为30 mAh/cm²，这是现有阴极容量的6倍。此外，采用MIEC/电解质/MIEC结构实现了18.5 Ah/cm²的累积锂电镀容量，如果与5 mAh/cm²的现有阴极面积容量配对，预计将产生3700次循环，大大超过了商用电动汽车电池寿命的要求。
