Magnesium-lithium hybrid batteries (MLHBs) have gained increasing attention due to their combined advantages of rapid ion insertion/extraction cathode and magnesium metal anode. Herein, SnS₂-SPAN hybrid cathode with strong C-Sn bond and rich defects is ingeniously constructed to realize Mg²⁺/Li⁺ co-intercalation. The physical and chemical double-confinement synergistic engineering of sulfurized polyacrylonitrile can suppress the agglomeration of SnS₂ nanoparticles and the volume expansion, simultaneously promote charge transfer and enhance structural stability. The introduced abundant sulfur vacancies provide more active sites for Mg²⁺/Li⁺ co-intercalation. Meanwhile, the beneficial effects of rich sulfur defects and C-Sn bond on enhanced electrochemical properties are further evidenced by density-functional theory (DFT) calculations. Therefore, compared with pristine SnS₂, SnS₂-SPAN cathode displays high specific capacity (218 mAh g⁻¹ at 0.5 A g⁻¹ over 700 cycles) and ultra-long cycling life (101 mAh g⁻¹ at 5 A g⁻¹ up to 28,000 cycles). And a high energy density of 307 Wh kg⁻¹ can be realized by the SnS₂-SPAN//Mg pouch cell. Such elaborate and simple design supplies a reference for the exploitation of advanced cathode materials with excellent electrochemical properties for MLHBs.

Developing an effective method to synthesize high-performance high-voltage LiCoO₂ is essential for its industrialization in lithium batteries (LIBs). This work proposes a simple mass-produced strategy for the first time, that is, negative temperature coefficient thermosensitive Pr₆O₁₁ nanoparticles are uniformly modified on LiCoO₂ to prepare LiCoO₂@Pr₆O₁₁ (LCO@PrO) via a liquid-phase mixing combined with annealing method. Tested at 274 mA g⁻¹, the modified LCO@PrO electrodes deliver excellent 4.5 V high-voltage cycling performance with capacity retention ratios of 90.8% and 80.5% at 25 and 60 ℃, being much larger than those of 22.8% and 63.2% for bare LCO electrodes. Several effective strategies were used to clearly unveil the performance enhancement mechanism induced by Pr₆O₁₁ modification. It is discovered that Pr₆O₁₁ can improve interface compatibility, exhibit improved conductivity at elevated temperature, thus enhance the Li⁺ diffusion kinetics, and suppress the phase transformation of LCO and its resulting mechanical stresses. The 450 mAh LCO@PrO‖graphite pouch cells show excellent LIB performance and improved thermal safety characteristics. Importantly, the energy density of such pouch cell was increased even by ~42% at 5 C. This extremely convenient technology is feasible for producing high-energy density LIBs with negligible cost increase, undoubtedly providing important academic inspiration for industrialization.

All-solid-state thin-film lithium batteries (TFLBs) are the ideal wireless power sources for on-chip micro/nanodevices due to the significant advantages of safety, portability, and integration. As the bottleneck for increasing the energy density of TFLBs, the key components of cathode, electrolyte, and anode are still underway to be improved. In this review, a brief history of TFLBs is first outlined by presenting several TFLB configurations. Based on the state-of-the-art materials developed for lithium-ion batteries (LIBs), the challenges and related strategies for the application of those potential electrode and electrolyte materials in TFLBs are discussed. Given the advanced manufacture and characterization techniques, the recent advances of TFLBs are reviewed for pursuing the high-energy-density and long-term-durability demands, which could guide the development of future TFLBs and analogous all-solid-state lithium batteries.