摘要
固态金属锂电池有望实现高达500 Wh/kg的高能量密度,因此是实现新能源汽车续航里程突破的关键电化学储能体系。然而,金属锂负极与固体电解质之间较差的接触稳定性严重制约了其循环性能。实验从固体电解质与金属锂负极间界面相的体积应变入手提升界面稳定性。不同于常规的高电化学活性修饰层,在固体电解质与金属锂负极之间引入了具有较低电化学活性的铜薄膜修饰层,因此能够大大降低界面相体积变化率,从而增强界面接触的稳定性,使固态金属锂电池的循环性能获得提升。通过电化学阻抗谱发现,铜薄膜的引入能够将固态电池负极界面单位面积面阻抗由2 030Ω/cm降低至65Ω/cm;钴酸锂正极的克容量发挥从118 mAh/g提升至145 mAh/g;固态金属锂电池0.33 C条件下循环500圈,容量保持率从46.3%提升至93.5%。
Solid metal lithium battery is expected to achieve a high energy density of 500 Wh/kg,which is regarded as the key electrochemical energy storage system to achieve a breakthrough in the driving range for new energy vehicles.However,the poor contact stability between the metal Li anode and the solid electrolyte seriously restricts its cycling performance.In this study,the interfacial stability was modified in the aspect of the volume strain of the interphase between the solid electrolyte and Li anode.Different from the conventional modification strategy with high electrochemical activity interphase,a copper film modified layer with low electrochemical activity between the solid electrolyte and the Li anode is introduced,so that the volume change ratio of the interface phase can be greatly reduced,thus enhancing the stability of the interface contact and improving the cycle stability of the solid lithium metal battery.According to the electrochemical impedance spectroscopy,it is found that the area specific resistance of the anode interface is reduced from 2030Ω/cm to 65Ω/cm by the introduction of copper thin film.The gram capacity of lithium cobalt oxide cathode is increased from 118 to 145 mAh/g.Moreover,the capacity retention of the solid-state lithium battery at 0.33 C after 500 cycles is increased from 46.3%to 93.5%.
作者
游志平
马宏
赵明
YOU Zhiping;MA Hong;ZHAO ming(Xiangyang Auto vocational technical college,New Energy Automotive Academy,Xiangyang,441000,China;NR Electric Co.,Ltd.,Nanjing 210000,China;Tianneng Battery Group Co.Ltd.,Huzhou 313100,China)
出处
《粉末冶金工业》
北大核心
2025年第3期149-155,共7页
Powder Metallurgy Industry
基金
浙江省重点研发计划资助项目(2020A01006)
关键词
铜薄膜
固态电池
界面修饰
循环稳定性
枝晶
Cu thin film
solid-state battery
interface modification
cycling stability
dendrite
