Meng Xiangyu, Sun Yufeng, Yu Mengzhou, Wang Zhiyu, Qiu Jieshan
State Key Lab of Fine Chemicals Liaoning Key Lab for Energy Materials and Chemical Engineering Dalian University of Technology Dalian 116024 China.
State Key Laboratory of Space Power-Sources Technology Shanghai Institute of Space Power-Sources Shanghai 200245 China.
Small Sci. 2021 Jul 16;1(9):2100021. doi: 10.1002/smsc.202100021. eCollection 2021 Sep.
Li metal batteries offer the ultimate choice of high-energy power source, but suffer the performance decay and safety risk originated from notorious dendrite problem and infinite volume change of Li metal anode. Herein, it is reported to strengthen the Li metal anode by ultralight but highly robust MXene aerogels (ULRMA) with build-in strain-resistant and molecular-level lithiophilic properties. A hydrogen-bonding crosslinking strategy is developed for rapidly assembling 2D MXene to ULRMA at ambient conditions with less sacrifice of intrinsic properties of MXene. The ULRMA with an ultralow density below 10 mg cm are favorable to maximize the merit of Li metal in gravimetric energy density while offering exceptional stability of porous frameworks against mechanical strain of long-term Li plating/stripping. The lithiophilic architecture with high conductivity and hierarchical porosity further largely reduces the potential polarization and guides the pattern of Li deposition. Uptaking Li metal into ULRMA leads to a stable Li metal anode with an ultralong lifetime of 1600 h with a high-rate response up to 20 mA cm and high coulombic efficiency. It yields a highly robust Li metal anode with high effectiveness in engineering stable Li-ion and Li-S batteries even paring with commercial LiFePO or sulfur cathode without nanostructuring.
锂金属电池提供了高能量电源的终极选择，但却因臭名昭著的枝晶问题和锂金属阳极的无限体积变化而遭受性能衰减和安全风险。在此，据报道通过具有内置抗应变和分子级亲锂特性的超轻但高度坚固的MXene气凝胶（ULRMA）来强化锂金属阳极。开发了一种氢键交联策略，用于在环境条件下将二维MXene快速组装成ULRMA，同时较少牺牲MXene的固有特性。密度低于10 mg cm的超低密度ULRMA有利于最大限度地发挥锂金属在重量能量密度方面的优点，同时提供多孔框架对长期锂电镀/剥离机械应变的卓越稳定性。具有高导电性和分级孔隙率的亲锂结构进一步大大降低了电位极化，并引导锂沉积模式。将锂金属引入ULRMA会产生一个稳定的锂金属阳极，其超长寿命为1600小时，高倍率响应高达20 mA cm，库仑效率高。它产生了一种高度坚固的锂金属阳极，在制造稳定的锂离子和锂硫电池方面非常有效，甚至与商业LiFePO或硫阴极配对时无需纳米结构化。
