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Lithium metal anode is regarded as the ultimate choice for next-generation energy storage systems, due to the lowest negative electrochemical potential and super high theoretical specific capacity. However, the growth of lithium dendrite during the cycling process is still one of the most critical bottlenecks for its application. In this work, a slurry-like hybrid electrolyte is proposed towards the application for lithium metal anode, which is composed of a liquid electrolyte part and a nanometric silane-Al2O3 particle part. The hybrid electrolyte shows high ionic conductivity (3.89 × 10−3 S cm−1 at 25 °C) and lithium-ion transference number (0.88). Especially, the resistance of hybrid electrolyte decreases compared to that of liquid electrolyte, while the viscosity of hybrid electrolyte increases. It is demonstrated that the hybrid electrolyte can effectively suppress the growth of lithium dendrite. Stable cycling of Li/Li cells at a current density up to 1 mA cm−2 is possible. The hybrid electrolyte helps to uniform the lithium ion flux inside the battery and partly comes from the formation of a rigid and highly conductive hybrid interfacial layer on the surface of lithium metal. This work not only provides a fresh way to stabilize lithium metal anode but also sheds light on further research for electrolyte optimization and design of lithium metal battery system.

Lithium metal is considered to be the most promising anode material due to its high theoretical capacity, low density and low electrochemical potential. However, continuous lithium dendrite growth results in low coulombic efficiency, capacity decay and safety hazard, which hinder the practical application of lithium metal anode. In this work, a functional polydopamine (PDA) layer inspired by nature is introduced to the surface of Cu foil, which is used as a current collector for lithium metal anode here. During depositing of lithium, lithium ions will firstly react with the hydroxyl groups of PDA layer, yielding uniformly distributed lithium complexing carbonyl groups which can work as nucleation sites and is favorable for uniform and stable deposition of lithium metal on the current collector, thus effectively suppress dendrite formation and growth. As a result, lithium metal batteries with PDA modified current collectors exhibit high coulombic efficiency of above 97% for 100 cycles at 0.5 mA cm-2 and the Li/Li symmetric cells show more than 800 h stable repeated lithium plating and stripping. The LiFePO4/Li batteries with the modified current collectors show extended cycle life (more than 150 cycles). This work provides a novel way to address the problems of lithium metal anode.

Antimony (Sb) has been regarded as one of the most promising anode materials for both lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs) and attracted much attention in recent years. Alleviating the volumetric effect of Sb during charge and discharge processes is the key point to promote Sb-based anodes to practical applications. Carbon dioxide (CO2) activation is applied to improve the rate performance of the Sb/C nanohybrid anodes caused by the limited diffusion of Li/Na ions in excessive carbon components. Based on the reaction between CO2 and carbon, CO2 activation can not only reduce the excess carbon content of the Sb/C nanohybrid but also create abundant mesopores inside the carbon matrix, leading to enhanced rate performance. Additionally, CO2 activation is also a fast and facile method, which is perfectly suitable for the fabrication system we proposed. As a result, after CO2 activation, the average capacity of the Sb/C nanohybrid LIB anode is increased by about 18 times (from 9 mA h g−1 to 160 mA h g−1) at a current density of 3300 mA g−1. Moreover, the application of the CO2-activated Sb/C nanohybrid as a SIB anode is also demonstrated, showing good electrochemical performance.

Metallic lithium, with super high theoretical specific capacity, enjoys great potential as an anode for rechargeable batteries. However, safety issues caused by lithium dendrite growth as well as limited cycling life restrict its practical application. Herein we validate that the application of a new dual-salt electrolyte composed of Lithium difluorophosphate (LiPO2F2) and lithium bis(fluorosulfony)imide (LiFSI) in the same proportion enables the improved long-term cycling performance along with high coulombic efficiency for lithium metal batteries. With 1 M LiPO2F2 and 1 M LiFSI in 1,2-dimethoxyethane as the electrolyte, a Li/Cu cell can be cycled at 1 mA for more than 300 cycles with a deposited capacity of 1.0 mAh. It also displays that a homogeneous and dendrite free solid electrolyte interphase layer is generated on the Cu electrode, which can be ascribed to the favorable stability of LiPO2F2 and high ionic conductivity of LiFSI. These results deliver perceptions for the advancement of high-performance lithium metal anode.

One of the crucial challenge for developing high safety and high voltage lithium ion batteries is to find a reliable electrolyte system. In this work, we report a kind of hybrid electrolytes, which are used for high-voltage lithium ion batteries and are expected to be able to effectively enhance the battery safety. The hybrid electrolytes are obtained by incorporating silane-Al2O3 (Al2O3-ST) into liquid electrolyte, which combines the merits of both solid electrolyte and liquid electrolyte. The Al2O3-ST nanoparticles help to increase lithium-ion transference number and to enhance battery safety, while liquid electrolyte contributes to high ionic conductivity. The cycling stability and rate capacity of LiNi0.5Mn1.5O4/Li batteries are improved by using the hybrid electrolytes. Nail-penetration tests indicate that LiNi0.6Mn0.2Co0.2O2/graphite battery with hybrid electrolyte owns obviously enhanced safety than that using traditional liquid electrolyte. This work provides new insight on electrolyte design for high-safety high-voltage lithium ion batteries.