State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, P. R. China.
State Key Laboratory of High Performance Ceramics and Superfine Microstructures, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, 200050, P. R. China.
Adv Mater. 2018 Aug;30(35):e1801409. doi: 10.1002/adma.201801409. Epub 2018 Jul 11.
Boron, the most ideal lithium-ion battery anode material, demonstrates highest theoretical capacity up to 12 395 mA h g when forming Li B. Furthermore, it also exhibits promising features such as light weight, considerable reserves, low cost, and nontoxicity. However, boron-based materials are not in the hotspot list because Li B may only exist when B is in atomically isolated/dispersed form, while the aggregate material can barely be activated to store/release Li. At this time, an ingenious design is demonstrated to activate the inert B to a high specific capacity anode material by dispersing it in a Fe matrix. The above material can be obtained after an electrochemical activation of the precursors Fe B/Fe and B O /Fe. The latter harvests the admirable capacity, ultrahigh tap density of 2.12 g cm , excellent cycling stability of 3180 mA h cm at 0.1 A g (1500 mA h g ) after 250 cycles, and superlative rate capability of 2650 mA h cm at 0.5 A g , 2544 mA h cm at 1.0 A g , and 1696 mA h cm at 2.0 A g . Highly conductive matrix promoted reversible Li storage of boron-based materials might open a new gate for advanced anode materials.
硼是最理想的锂离子电池阳极材料，形成 LiB 时具有高达 12395 mA h g 的最高理论容量。此外，它还具有重量轻、储量可观、成本低、无毒等特点。然而，硼基材料不在热点清单上，因为只有当 B 处于原子隔离/分散状态时，LiB 才可能存在，而聚合材料几乎无法被激活来存储/释放 Li。此时，通过将其分散在 Fe 基体中，展示了一种巧妙的设计来将惰性 B 激活为高比容量的阳极材料。上述材料可以通过对前驱体 FeB/Fe 和 B2O3/Fe 的电化学激活来获得。后者在 0.1 A g（1500 mA h g）下具有优异的循环稳定性，经过 250 次循环后可获得 3180 mA h cm 的超高容量、2.12 g cm 的超高堆积密度、2650 mA h cm 的出色倍率性能，在 0.5 A g、1.0 A g 和 2.0 A g 时分别为 2544 mA h cm 和 1696 mA h cm。高导电性基体促进了硼基材料可逆的 Li 存储，这可能为先进的阳极材料开辟了一个新的途径。
