Lithium-Ion Charged Polymer Channels Flattening Lithium Metal Anode

Abstract

The concentration difference in the near-surface region of lithium metal is the main cause of lithium dendrite growth. Resolving this issue will be key to achieving high-performance lithium metal batteries (LMBs). Herein, we construct a lithium nitrate (LiNO3)-implanted electroactive β phase polyvinylidene fluoride-co-hexafluoropropylene (PVDF-HFP) crystalline polymorph layer (PHL). The electronegatively charged polymer chains attain lithium ions on the surface to form lithium-ion charged channels. These channels act as reservoirs to sustainably release Li ions to recompense the ionic flux of electrolytes, decreasing the growth of lithium dendrites. The stretched molecular channels can also accelerate the transport of Li ions. The combined effects enable a high Coulombic efficiency of 97.0% for 250 cycles in lithium (Li)||copper (Cu) cell and a stable symmetric plating/stripping behavior over 2000 h at 3 mA cm−2 with ultrahigh Li utilization of 50%. Furthermore, the full cell coupled with PHL-Cu@Li anode and LiFePO4 cathode exhibits long-term cycle stability with high-capacity retention of 95.9% after 900 cycles. Impressively, the full cell paired with LiNi0.87Co0.1Mn0.03O2 maintains a discharge capacity of 170.0 mAh g−1 with a capacity retention of 84.3% after 100 cycles even under harsh condition of ultralow N/P ratio of 0.83. This facile strategy will widen the potential application of LiNO3 in ester-based electrolyte for practical high-voltage LMBs.

Electrochemical coupling in subnanometer pores/channels for rechargeable batteries

“…641 For instance, Li metal anodes could deliver the highest theoretical capacity of 3860 mA h g −1 for LIBs as compared to all other kinds of anodes. 642,643 Whereas metal anodes exhibit all the problems of other types of anodes, and the extent is much more serious. Besides, the metal anodes are prone to dendrite growth caused by internal short circuits, posing serious safety concerns for the practical application of the metal batteries.…”

Dual-Defect Engineering Strategy Enables High-Durability Rechargeable Magnesium-Metal Batteries

“…Rechargeable magnesium-metal batteries (RMMBs) have emerged as promising next-generation energy-storage devices, surpassing lithium-ion batteries (LIBs) due to their high theoretical volumetric capacity (3833 mAh cm −3 ) and natural abundance (ranked 3rd in seawater and 8th in the earth’s crust) as well as the lower redox potential (− 2.37 V vs. standard hydrogen electrode) of the magnesium-metal anodes [ 1 – 4 ]. Furthermore, the absence of sharp dendrites in magnesium-metal anodes ensures the safety of RMMBs over LIBs [ 5 , 7 ].…”

Constructing sodiophilic interconnected ion-transport channels towards a stable Na-metal anode

“…These channels act as reservoirs to sustain the flow of Na + ions into or out of the electrode, similar to an expressway for high-speed ion transport. 32,33 Consequently, the interconnected ion transport channels ensure a homogeneous ion distribution. This design also reduces the diffusion energy barrier, accelerates Na + ion migration, and inhibits the formation of sodium dendrites.…”