School of Materials Science and Engineering, Wuhan University of Technology, Wuhan, 430070, P. R. China.
Collaborative Innovation Center for Advanced Organic Chemical Materials Co-constructed by the Province and Ministry, Ministry of Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules, College of Chemistry and Chemical Engineering, Hubei University, Wuhan, 430062, P. R. China.
Small. 2023 Jun;19(26):e2300762. doi: 10.1002/smll.202300762. Epub 2023 Mar 22.
Li/CF battery is one of the most promising lithium primary batteries (LPBs) which yields the highest energy density but with poor rate capability. This Achilles'' heel hinders the large-scale applications of Li/CF batteries. This work first reports a facile chemical modification method of CF with δ-MnO . Having benefited from the chemical bonding, the electrochemical performance at high-rate discharge is remarkably enhanced without compromising the specific capacity. The coin cells exhibit an energy density of 1.94 × 10 Wh kg at 0.2 C, which is approaching the theoretical energy density of commercial fluorinated graphite (2.07 × 10 Wh kg ). A power density of 5.49 × 10 W kg at 40 C associated with an energy density of 4.39 × 10 Wh kg , which is among the highest value of Li/CF batteries, are obtained. Besides, the punch batteries achieve an ultrahigh power density of 4.39 × 10 W kg with an energy density of 7.60 × 10 Wh kg at 30 C. The intrinsic reasons for this outstanding electrochemical performance, which are known as the fast Li diffusion kinetics guided by thin δ-MnO flakes and the low formation energy barrier caused by chemical bonding, are explored by the galvanostatic intermittent titration technique (GITT) and theoretical calculations.
锂/碳纤维(CF)电池是最有前途的锂一次电池(LPB)之一,其能量密度最高,但倍率性能较差。这个缺点阻碍了锂/ CF 电池的大规模应用。本工作首次报道了一种简便的 CF 化学改性方法,用 δ-MnO 进行化学修饰。得益于化学键的形成,高倍率放电的电化学性能得到了显著提高,而比容量没有降低。扣式电池在 0.2 C 时的能量密度为 1.94 × 10 Wh kg ,接近商用氟化石墨(2.07 × 10 Wh kg )的理论能量密度。在 40 C 时获得了 5.49 × 10 W kg 的功率密度和 4.39 × 10 Wh kg 的能量密度,这是锂/ CF 电池中最高的值之一。此外,打孔电池在 30 C 时实现了 4.39 × 10 W kg 的超高功率密度和 7.60 × 10 Wh kg 的能量密度。通过恒电流间歇滴定技术(GITT)和理论计算,探讨了这种出色电化学性能的内在原因,即薄 δ-MnO 片引导的快速 Li 扩散动力学和化学键引起的低形成能垒。