Zhou Yongning group of Fudan University has made new progress in the design of high performance composite lithium anode

With the rapid development of large capacity mobile energy storage applications such as electric vehicles, traditional lithium-ion batteries can no longer meet the demand Therefore, it is urgent to develop the next generation lithium battery with high energy density and long cycle life Due to its high theoretical specific capacity and low electrochemical potential, lithium metal is considered to be the most potential anode material for the next generation of lithium batteries However, there are some essential problems in the process of lithium deposition / stripping, such as the vertical growth of lithium dendrite and large volume change, which seriously hinder the practical application of lithium metal anode Recently, the Zhou Yongning research group of the Department of materials science, Fudan University has obtained the latest research results in the design of high-performance lithium metal composite anode It is used to induce the transverse growth of lithium dendrites in the cupric copper coated copper foam skeleton ("Cuprite-coated Cu foam skeleton host enabling lateral growth oflithium dendrites for for" ”）Published in energy storage materials (DOI: 10.1016/j.ensm 2018.12.007), an authoritative journal in the field of energy materials At present, the metal lithium anode is facing the following challenges: 1 The lithium dendrites growing perpendicular to the electrode surface during the cycle of the battery will pierce the battery diaphragm, resulting in the internal short circuit of the battery In serious cases, it will cause the battery to fire or even explode; 2 The growing dendrites will consume more electrolyte and form an unstable solid electrolyte interface (SEI) layer, which will lead to the rapid decline of battery capacity; 3 Due to the growth and fracture of dendrites and the change of electrode volume, the surface of lithium metal anode will form a "dead" layer of electrical insulation, which is another important factor leading to the deterioration of battery performance The Zhou Yongning group has successfully synthesized a composite lithium metal anode (CCOF-Li) which can induce transverse growth of lithium metal by melting lithium method They use foam copper as skeleton and grow a Cu 2+1 O oxide layer on the surface of lithium foam Under the premise of guaranteeing the mechanical properties of the framework, the lithium wettability of the foam copper is significantly improved, so that the molten lithium can rapidly infiltrate into the foam copper skeleton to form a composite lithium metal with three dimensional skeleton support This special electrode structure can provide space and conditions for the growth of lithium metal in the direction parallel to the electrode surface, thus inhibiting the growth of lithium metal in the direction perpendicular to the electrode surface and the formation of "dead" lithium layer In addition, the three-dimensional framework can reduce the local current density of the electrode, form a uniform lithium deposition / stripping behavior, and buffer the electrode volume change during charging and discharging When the composite metal lithium anode is applied to the lithium sulfur battery, the cycle performance and rate performance of the battery are significantly improved The first author of this paper is Yue Xinyang, a doctoral student in the Department of materials science, and the corresponding author is Zhou Yongning The research work was supported by the youth thousand talents program of the central organization department.