The heteroatom doping strategies have been utilized to effectively improve the performance of the carbon-based hosts, such as graphene, for lithium (Li) metal in high energy density lithium metal batteries. However, solely doped graphene hosts often need the assistance of other materials with either better lithiophilicity or electronic conductance to achieve smooth and efficient deposition of Li, which adds extra weight or volume. Herein, graphene co-doped by nitrogen and fluorine (NFG) is employed as a stable host for Li, where the N-doping provides lithiophilicity and electronic conductivity lacked by F-doping and the F-doping facilitate fast formation of solid electrolyte interphase (SEI) retarded by N-doping. The well regulation of Li plating/stripping and SEI formation is verified by quickly stabilized and small-magnitude voltage hysteresis, which stands out in Li hosts based on doped graphene and leads to excellent long-term cycling performance of NFG based electrodes. A voltage hysteresis of 20 mV is observed for more than 850 h in the symmetrical cell. The remarkable efficiency of lithium usage is confirmed by the high-capacity retention of a full cell paired with LFP, which exceeds 70% after 500 cycles. This work presents an innovative perspective on the control of Li plating/stripping by simultaneously introducing two kinds of dopants into graphene and paving the way for exploring practical Li metal batteries.

The easy oxidation and surface roughness of Cu nanowire (NW) films are the main bottlenecks for their usage in transparent conductive electrodes (TCEs). Herein, we have developed a facile and scaled-up solution route to prepare Cu NW-based TCEs by embedding Cu NWs into pre-coated smooth poly(3, 4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT: PSS) films on poly(ethylene terephthalate) (PET) substrates. The so obtained Cu NW-PEDOT: PSS/PET films have low surface roughness (~70 nm in height), high stability toward oxidation and good flexibility. The optimal TCEs show a typical sheet resistance of 15 Ω·sq^-1 at high transparency (76% at λ = 550 nm) and have been used successfully to make polymer (poly(3-hexylthiophene): phenyl-C61-butyric acid methyl ester) solar cells, giving an efficiency of 1.4%. The overall properties of Cu NW-PEDOT: PSS/PET films demonstrate their potential application as a replacement for indium tin oxide in flexible solar cells.