WPI Advanced Institute for Materials Research, Tohoku University, Sendai, 980-8577, Japan.
Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD, 21218, USA.
Adv Mater. 2019 Jan;31(2):e1805334. doi: 10.1002/adma.201805334. Epub 2018 Nov 6.
The key bottlenecks hindering the practical implementations of lithium-metal anodes in high-energy-density rechargeable batteries are the uncontrolled dendrite growth and infinite volume changes during charging and discharging, which lead to short lifespan and catastrophic safety hazards. In principle, these problems can be mitigated or even solved by loading lithium into a high-surface-area, conductive, and lithiophilic porous scaffold. However, a suitable material that can synchronously host a large loading amount of lithium and endure a large current density has not been achieved. Here, a lithiophilic 3D nanoporous nitrogen-doped graphene as the sought-after scaffold material for lithium anodes is reported. The high surface area, large porosity, and high conductivity of the nanoporous graphene concede not only dendrite-free stripping/plating but also abundant open space accommodating volume fluctuations of lithium. This ingenious scaffold endows the lithium composite anode with a long-term cycling stability and ultrahigh rate capability, significantly improving the charge storage performance of high-energy-density rechargeable lithium batteries.
高能量密度可再充电锂电池中，锂金属阳极实际应用的主要瓶颈是在充放电过程中不可控的枝晶生长和无限的体积变化，这导致了短寿命和灾难性的安全隐患。原则上，这些问题可以通过将锂装入高表面积、导电和亲锂多孔支架来缓解甚至解决。然而，还没有找到一种合适的材料，既能同步容纳大量的锂负载，又能承受大电流密度。在这里，报道了一种亲锂的 3D 纳米多孔氮掺杂石墨烯作为锂阳极的理想支架材料。纳米多孔石墨烯的高表面积、大孔隙率和高导电性不仅使无枝晶剥离/电镀成为可能，而且还为容纳锂的体积变化提供了丰富的开放空间。这种巧妙的支架赋予了锂复合阳极长期的循环稳定性和超高的倍率性能，显著提高了高能量密度可再充电锂电池的电荷存储性能。
