Browsing by Author "Peng, Zhijian"
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- Lithium–copper alloy embedded in 3D porous copper foam with enhanced electrochemical performance toward lithium metal batteriesPublication . Lu, Ziyu; Tai, Zhixin; Yu, Zhipeng; LaGrow, Alec P.; Bondarchuk, Oleksandr; Sousa, Juliana P.S.; Meng, Lijian; Peng, Zhijian; Liu, LifengSuppressing dendrite growth and accommodating volume change, among others, are the main challenges for lithium (Li) metal anode to be used in rechargeable Li batteries. The commercial macroporous copper (Cu) foam current collector may only tackle these challenges to a little extent, and it is usually unable to provide sufficient Li nucleation sites, leading to rapidly increased polarization and unstable cycling performance. Herein, we report a three-dimensional composite anode comprising Li–Cu alloy melt-cast on a commercial Cu foam (CF) current collector (Li–Cu/CF), which can be converted to a unique architecture consisting of Li metal supported by an interconnected CuLix alloy nanowire network formed because of the phase separation, when the molten Li–Cu alloy cools down and gets solidified. Compared to the bare Li foil, the Li–Cu/CF anode shows a smaller polarization and better cycle stability in the carbonate electrolyte at various current densities ranging from 1 to 5 mA/cm2 and is free from dendrite growth upon repeated Li plating/stripping. This can be attributed to the low Li nucleation overpotential and high Coulombic efficiency (96%) during Li plating on and stripping from the thus-obtained hierarchically structured CF collector, as well as the higher proportion of Li2O relative to LiF in the solid-electrolyte interphase layer. Moreover, when assembled in a full cell paired with the LiFePO4 cathode, the Li–Cu/CF anode also exhibits much better rate capability and cycle performance than the bare Li foil. Our work provides a new convenient approach to construct a dendrite-free Li metal anode that can be potentially deployed in the next-generation high energy density rechargeable Li batteries.
- Novel Quasi‐Liquid K‐Na Alloy as a Promising Dendrite‐Free Anode for Rechargeable Potassium Metal BatteriesPublication . Tai, Zhixin; Li, Yi; Liu, Yajie; Zhao, Lanling; Ding, Yu; Lu, Ziyu; Peng, Zhijian; Meng, Lijian; Yu, Guihua; Liu, LifengRechargeable potassium metal batteries are promising energy storage devices with potentially high energy density and markedly low cost. However, eliminating dendrite growth and achieving a stable electrode/electrolyte interface are the key challenges to tackle. Herein, a novel "quasi-liquid" potassium-sodium alloy (KNA) anode comprising only 3.5 wt% sodium (KNA-3.5) is reported, which exhibits outstanding electrochemical performance able to be reversibly cycled at 4 mA cm-2 for 2000 h. Moreover, it is demonstrated that adding a small amount of sodium hexafluorophosphate (NaPF6 ) into the potassium bis(fluorosulfonyl)imide electrolyte allows for the formation of the "quasi-liquid" KNA on electrode surface. Comprehensive experimental studies reveal the formation of an unusual metastable KNa2 phase during plating, which is believed to facilitate simultaneous nucleation and suppress the growth of dendrites, thereby improving the electrode's cycle lifetime. The "quasi-liquid" KNA-3.5 anode demonstrates markedly enhanced electrochemical performance in a full cell when pairing with Prussian blue analogs or sodium rhodizonate dibasic as the cathode material, compared to the pristine potassium anode. Importantly, unlike the liquid KNA reported before, the "quasi-liquid" KNA-3.5 exhibits good processability and can be readily shaped into sheet electrodes, showing substantial promise as a dendrite-free anode in rechargeable potassium metal batteries.
- Novel Quasi‐Liquid K‐Na Alloy as a Promising Dendrite‐Free Anode for Rechargeable Potassium Metal BatteriesPublication . Tai, Zhixin; Li, Yi; Liu, Yajie; Zhao, Lanling; Ding, Yu; Lu, Ziyu; Peng, Zhijian; Meng, Lijian; Yu, Guihua; Liu, LifengRechargeable potassium metal batteries are promising energy storage devices with potentially high energy density and markedly low cost. However, eliminating dendrite growth and achieving a stable electrode/electrolyte interface are the key challenges to tackle. Herein, a novel “quasi-liquid” potassium-sodium alloy (KNA) anode comprising only 3.5 wt% sodium (KNA-3.5) is reported, which exhibits outstanding electrochemical performance able to be reversibly cycled at 4 mA cm–2 for 2000 h. Moreover, it is demonstrated that adding a small amount of sodium hexafluorophosphate (NaPF6) into the potassium bis(fluorosulfonyl)imide electrolyte allows for the formation of the “quasi-liquid” KNA on electrode surface. Comprehensive experimental studies reveal the formation of an unusual metastable KNa2 phase during plating, which is believed to facilitate simultaneous nucleation and suppress the growth of dendrites, thereby improving the electrode's cycle lifetime. The “quasi-liquid” KNA-3.5 anode demonstrates markedly enhanced electrochemical performance in a full cell when pairing with Prussian blue analogs or sodium rhodizonate dibasic as the cathode material, compared to the pristine potassium anode. Importantly, unlike the liquid KNA reported before, the “quasi-liquid” KNA-3.5 exhibits good processability and can be readily shaped into sheet electrodes, showing substantial promise as a dendrite-free anode in rechargeable potassium metal batteries.