Lee Sang-Min, Kim Junyoung, Moon Janghyuk, Jung Kyu-Nam, Kim Jong Hwa, Park Gum-Jae, Choi Jeong-Hee, Rhee Dong Young, Kim Jeom-Soo, Lee Jong-Won, Park Min-Sik
Battery Research Center, Korea Electrotechnology Research Institute, 12 Bulmosan-ro 10 beon-gil, Changwon, 51543, Republic of Korea.
Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, 1732 Deogyeong-daero, Giheung-gu, Yongin, 17104, Republic of Korea.
Nat Commun. 2021 Jan 4;12(1):39. doi: 10.1038/s41467-020-20297-8.
The realisation of fast-charging lithium-ion batteries with long cycle lifetimes is hindered by the uncontrollable plating of metallic Li on the graphite anode during high-rate charging. Here we report that surface engineering of graphite with a cooperative biphasic MoO-MoP promoter improves the charging rate and suppresses Li plating without compromising energy density. We design and synthesise MoO-MoP/graphite via controllable and scalable surface engineering, i.e., the deposition of a MoO nanolayer on the graphite surface, followed by vapour-induced partial phase transformation of MoO to MoP. A variety of analytical studies combined with thermodynamic calculations demonstrate that MoO effectively mitigates the formation of resistive films on the graphite surface, while MoP hosts Li at relatively high potentials via a fast intercalation reaction and plays a dominant role in lowering the Li adsorption energy. The MoO-MoP/graphite anode exhibits a fast-charging capability (<10 min charging for 80% of the capacity) and stable cycling performance without any signs of Li plating over 300 cycles when coupled with a LiNiCoMnO cathode. Thus, the developed approach paves the way to the design of advanced anode materials for fast-charging Li-ion batteries.
在高倍率充电过程中，金属锂在石墨阳极上不可控的镀覆阻碍了具有长循环寿命的快速充电锂离子电池的实现。在此，我们报道了用协同双相MoO-MoP促进剂对石墨进行表面工程处理，可提高充电速率并抑制锂镀覆，同时不降低能量密度。我们通过可控且可扩展的表面工程设计并合成了MoO-MoP/石墨，即在石墨表面沉积MoO纳米层，随后通过气相诱导使MoO部分相转变为MoP。多种分析研究与热力学计算相结合表明，MoO有效地减轻了石墨表面电阻膜的形成，而MoP通过快速嵌入反应在相对较高的电位下容纳锂，并在降低锂吸附能方面起主导作用。当与LiNiCoMnO阴极耦合时，MoO-MoP/石墨阳极表现出快速充电能力（80%容量在<10分钟内充电）和稳定的循环性能，在300次循环中没有任何锂镀覆的迹象。因此，所开发的方法为设计用于快速充电锂离子电池的先进阳极材料铺平了道路。
