摘要
氧化锰(MnO)具有理论比容量高(756 mAh/g)、成本低、资源丰富等优势,被视为极具开发潜力的锂离子电池(LIBs)负极材料。然而,MnO负极材料存在导电性差、结构不稳定和体积易膨胀等问题,致使MnO负极的首次库仑效率低、倍率性能差且循环寿命短。为了解决以上问题,提出一种简单的水热自组装策略,以乙酰丙酮锰为Mn源,在MXene-Ti_(3)C_(2)T_(x)层间完成自组装,得到Ti_(3)C_(2)T_(x)夹层的“绣球花状”有机碳包覆锰基前驱体,经煅烧得到具有强界面键合(Mn—O—Ti)的MnO@Ti_(3)C_(2)T_(x)复合材料。该多级复合结构能够全面提升MnO的电荷传输效率及结构稳定性,抑制其体积膨胀,暴露更多活性位点,从而提高MnO负极的储锂性能。作为LIBs负极材料,最优的MnO@Ti_(3)C_(2)T_(x)负极在0.1 A/g下的首圈库仑效率为73.71%,经充分活化后的可逆比容量达到997.38 mAh/g,循环100圈后的容量保持率为95.11%,表现出高比容量和优异的循环稳定性。此外,在2 A/g下循环300圈,其可逆比容量为552.36 mAh/g,远高于不含Ti_(3)C_(2)T_(x)的MnO负极。研究为高性能锰基负极材料的可控制备提供了新的思路。
Manganese oxide(MnO)is regarded as a highly promising anode material for lithium-ion batteries(LIBs)due to its high theoretical specific capacity(756 mAh/g),low cost,and natural abundance.Nevertheless,MnO anode suffers from intrinsic drawbacks including inferior conductivity,structural instability,and significant volume expansion,resulting in low initial coulombic efficiency,poor rate and cycling performance.To address these challenges,a facile hydrothermal self-assembly strategy is proposed herein.Using manganese acetylacetonate as the Mn source,a hydrangea-like organic carbon-coated Mn-based precursor intercalated with MXene-Ti_(3)C_(2)T_(x)layers is synthesized,followed by calcination to obtain MnO@Ti_(3)C_(2)T_(x)composites with robust interfacial bonding(Mn-O-Ti).This hierarchical architecture synergistically enhances the charge transport efficiency and structural stability of MnO,suppresses volume expansion,and exposes abundant electroactive sites,thereby significantly improving the lithium storage performance.As a LIB anode,the optimized MnO@Ti_(3)C_(2)T_(x)delivers an initial Coulombic efficiency of 73.71%at 0.1 A/g and achieves a high reversible capacity of 997.38 mAh/g after activation.Notably,it retains 95.11%capacity retention after 100 cycles,demonstrating exceptional cycling stability.Even under a high current density of 2 A/g,it maintains a reversible capacity of 552.36 mAh/g over 300 cycles,far surpassing that of Ti_(3)C_(2)T_(x)-free MnO.This work provides a novel strategy for the controllable fabrication of high-performance Mn-based anode materials.
作者
孙衍鹍
李泽辰
王子昂
郑方植
廖思嘉
盘唐缘
叶强
肖志华
李永峰
徐春明
SUN Yankun;LI Zechen;WANG Ziang;ZHENG Fangzhi;LIAO Sijia;PAN Tangyuan;YE Qiang;XIAOZhihua;LI Yongfeng;XU Chunming(State Key Laboratory of Heavy Oil Processing,China University of Petroleum(Beijing),Beijing 102249,China;College of Carbon Neutrality Future Technology,China University of Petroleum(Beijing),Beijing 102249,China)
出处
《洁净煤技术》
北大核心
2025年第8期133-146,共14页
Clean Coal Technology
基金
中国石油大学(北京)校青年拔尖人才科研启动基金资助项目(ZX20230047)
国家自然科学基金资助项目(22408399,22238012)。
作者简介
孙衍鹍(1996-),男,山东潍坊人,博士研究生。E-mail:sunyankun_@outlook.com;通讯作者:肖志华(1991-),男,江西吉安人,副教授,博士。E-mail:xzh@cup.edu.cn;通讯作者:李永峰(1976-),男,吉林德惠人,教授,博士。E-mail:yfli@cup.edu.cn。
