LAUSR

Abstract Uncontrolled dendrite growth, continuous dead Li formation together with host-less volume changes associated with lithium metal greatly hamper the commercialization of high-energy-density lithium metal batteries (LMBs). Manipulating the deposition behavior of lithium ions is generally believed effective to root out undesired sharp protrusions over the anode surface and various kinds of 3D conductive inert substrates/hosts are introduced to mitigate volume changes and dead Li formation. However, the introduction of alien host would inevitably sacrifice partial energy density of cells. Herein, we successfully achieved in-situ deposition of a 3D continuous dendrite-free lithium deposition with blunt surface at the absence of inert host by simply adding an electrochemical active polymer-PMMA into the electrolyte to manipulate the deposition behavior of lithium ions. The function mechanism of PMMA upon Li deposition is investigated in detail. Upon discharging, lithium ions could react with PMMA and become immobilized. These pre-trapped lithium ions are then in-situ reduced into initial lithium seeds to guide sequential lithium deposition at the vicinity, ending up with a morphology modeled after the 3D PMMA molecular chains. Such morphology provides 3D continuous pathways for fast electron transport to eliminate dead Li formation without the help of foreign host. Li-LCO full cells equipped with such a 3D anode present greatly enhanced rate and cycle performance and highly preserved morphology upon rate testing and cycling.