Bo Wang

Abstract Uncontrolled dendrites resulting from nonuniform lithium (Li) nucleation/growth and Li volume expansion during charging cause serious safety problems for Li anode‐based batteries. Here the coating of nickel foam with graphitic carbon nitride (g‐C 3 N 4 ) to have a 3D current collector (g‐C 3 N 4 @Ni foam) for dendrite‐free Li metal anodes is reported. The lithiophilic g‐C 3 N 4 coupled with the 3D framework is demonstrated to be highly effective for promoting the uniform deposition of Li and suppressing the formation of dendrites. Both density functional theory calculations and experimental studies indicate the formation of a micro‐electric field resulting from the tri‐s‐triazine units of g‐C 3 N 4 , which induces numerous Li nuclei during the initial nucleation stage, effectively guiding the following Li growth on the 3D Ni foam to be well distributed. Furthermore, the 3D porous framework is favorable for absorbing any volume change and stabilizing the solid–electrolyte interphase layer during repeated Li plating/stripping. As such, a Li metal anode based on the g‐C 3 N 4 @Ni foam has a remarkable electrochemical performance with a high Coulombic efficiency (98% retention after 300 cycles), an ultralong lifespan up to 900 h, as well as a low overpotential (<15 mV at 1.0 mA cm −2 ) at a Li deposition of 9.0 mA h cm −2 .

Abstract Organosulfides are promising high‐capacity cathode materials for rechargeable lithium batteries. However, they are hindered by several key challenges including the electronic/ionic insulation and solubility issues of the discharged products. Herein, TiS 2 nanosheets@carbon nanotubes (TiS 2 NSs@MWCNT) are proposed as a promoter and booster toward phenyl tetrasulfide (PTS). It serves as a bifunctional mediator, not only anchoring active materials in the cathode through chemical adsorption but also facilitating the reaction kinetics. The Li‐organosulfide cell yields a reversible discharge capacity of 467.6 mAh g −1 and a high capacity retention of 81.9% after 200 cycles at 0.5 C rate. When the PTS areal mass loading is 5.8 mg cm −2 and the electrolyte/PTS ratio is 3.8 µL mg −1 , a high specific capacity of 444 mAh g −1 at 0.5 C rate can still be achieved. The strong anchoring and electrocatalysis effects of TiS 2 toward PhSLi and polysulfide are revealed using experimental and computational approaches. The study sheds light on metal sulfides as mediators to improve the cycling life of Li‐organosulfide batteries and provides deep comprehension of the instinct interaction evolution at molecular level, which is invaluable for fabrication of electrode materials.

Lithium–aluminum (LixAl, x = the molar ratio of Li to Al), an important alloy anode with a specific capacity over 2 times higher than that of the carbon anode used in commercial liquid electrolyte lithium-ion batteries (LELIBs), has been proven to be a failure in LELIBs due to the notorious pulverization phenomenon. However, whether or not such pulverization persists in all solid state lithium batteries (ASSLBs) remains unclear. Herein, we show that pulverization of the LixAl anode is mitigated in ASSLBs due to the applied external stack pressure, thus preventing the mechanical failure of the LixAl anode in ASSLBs. Moreover, electron microscopy investigation reveals that, instead of pulverization, electrochemomechanical stress induces 2 orders of magnitude grain size reduction from a few tens of microns to a few hundred nanometers. The grain-refined LixAl anode facilitates lithium ion transport, which improves the rate performance and specific capacity of the LixAl anode. Consequently, the assembled single-crystal LiNi0.83Co0.12Mn0.05O2|Li10Si0.3PS6.7Cl1.8|Li0.4Al ASSLBs reach 2000 cycles with a capacity retention of 100% at 3C (13.9 mA/cm2, room temperature), at a high areal capacity of 2.1 mAh/cm2. The all-solid pouch cell with a LixAl anode can reach an energy density of 219 Wh kg–1 based on the total mass of the cell. These results demonstrate the prospect of implementing the Al-based anode in ASSLBs for practical energy storage applications.