Double-layered skeleton of Li alloy anchored on 3D metal foam enabling ultralong lifespan of Li anode under high rate

The high specific capacity and low negative electrochemical potential of lithium metal anodes(LMAs),may allow the energy density threshold of Li metal batteries(LMBs)to be pushed higher.However,the existing detrimental issues,such as dendritic growth and volume expansion,have hindered the practical implementation of LMBs.Introducing three-dimensional frameworks(e.g.,copper and nickel foam),have been regarded as one of the fundamental strategies to reduce the local current density,aiming to extend the Sand'time.Nevertheless,the local environment far from the skeleton is almost the same as the typical plane Li,due to macroporous space of metal foam.Herein,we built a double-layered 3D current collector of Li alloy anchored on the metal foam,with micropores interconnected macropores,via a viable thermal infiltration and cooling strategy.Due to the excellent electronic and ionic conductivity coupled with favorable lithiophilicity,the Li alloy can effectively reduce the nucleation barrier and enhance the Li^(+)transportation rate,while the metal foam can role as the primary promotor to enlarge the surface area and buffer the dimensional variation.Synergistically,the Li composite anode with hierarchical structure of primary and secondary scaffolds realized the even deposition behavior and minimum volume expansion,outputting preeminent prolonged cycling performances under high rate.

Li-Zn alloy patch for defect-free polymer interface film enables excellent protection effect towards stable Li metal anode

Constructing a smart polymer film with favorable lithium(Li)transport capability and mechanical flexibility for suppressing Li dendrite growth is an effective strategy.Unfortunately,the porosity and the swelling of the polymer membrane cannot completely prevent liquid electrolyte from sweeping through the artificial protection film,severely deteriorating the cyclic performance.Herein,we propose a defectfree hybrid film that consists of Li+conductive lithium polyacrylate(LiPAA)polymer interface layer and Li-Zn alloy patch to tackle the critical problems of traditional polymer composite passivation film.The pinhole leaks of the polymer matrix are self-filled by Li-Zn alloy patches,enhancing the integrity of LiPAA film.Consequently,a defect-free hybrid film is nailed flat against the Li metal anode,exhibiting extraordinary stability in the liquid electrolyte and enabling perfect protection effect.This facile strategy produces a promising anode for next generation Li batteries.

Synergistic modulation of Li nucleation/growth enabled by CNTswrapped lithiophilic CoP/Co_(2)P decorated hollow carbon polyhedron host for stable lithium metal anodes

Infinite volume expansion and uncontrolled lithium dendrite growth are the main bottlenecks that greatly hinder the commercial application of lithium metal anodes.Herein,derived from zeolitic imidazolate framework(ZIF)-67,carbon nanotubes(CNTs)-wrapped and CoP/Co_(2)P uniformly distributed nitrogen-doped hollow porous polyhedron carbon(CNT-CoP@NC)is elaborately designed as lithium metal host.A hybrid of N-doping and metallic phosphides modifications improves the lithiophilicity and reduces the nucleation barrier,consequently leading to homogeneous nucleation and smooth deposition of metallic lithium,thus suppresses the growth of Li dendrites.Meanwhile,self-generated CNTs arrays efficiently reduce the local current density.Moreover,the reduced lithium is preferentially deposited into the hollow structure of CNT-CoP@NC and then filled the voids among the CNT-CoP@NC particles.This all-pervasive Li plating design can not only alleviate the volume effect,but also maximize the anode space utilization.Benefiting from these synergistic modulations,even with an ultra-thin(7.2μm)anode layer of CNT-CoP@NC host,a high Coulombic efficiency for more than 400 cycles and an extended lifespan of 1,700 h under 1 mA·cm^(−2)can be achieved.When paired with a competitive high mass loading(17.1 mg·cm^(−2))LiFePO4 cathode,a superb cycling stability(126.7 mAh·g^(−1)over 550 cycles)is recorded at 1 C.

Li-Ca Alloy Composite Anode with Ant-Nest-Like Lithiophilic Channels in Carbon Cloth Enabling High-Performance Li Metal Batteries

Constructing a three-dimensional(3D)multifunctional hosting architecture and subsequent thermal infusion of molten Li to produce advanced Li composite is an effective strategy for stable Li metal anode.However,the pure liquid Li is difficult to spread across the surface of various substrates due to its large surface tension and poor wettability,hindering the production and application of Li composite anode.Herein,heteroatomic Ca is doped into molten Li to generate Li-Ca alloy,which greatly regulates the surface tension of the molten alloy and improves the wettability against carbon cloth(CC).Moreover,a secondary network composed of CaLi2 intermetallic compound with interconnected ant-nest-like lithiophilic channels is in situ formed and across the primary scaffold of CC matrix by infiltrating molten Li-Ca alloy into CC and then cooling treatment(LCAC),which has a larger and lithiophilic surface to enable uniform Li deposition into interior space of the hybrid scaffold without Li dendrites.Therefore,LCAC exhibits a long-term lifespan for 1100 h under a current density of 5 mA cm^(-2)with fixed areal capacity of 5 mAh cm^(-2).Remarkably,full cells paired with practical-level LiFePO4 cathode of 2.45 mAh cm^(-2)deliver superior performance.