Reactivity at the Electrode-Electrolyte Interfaces in Li-Ion and Gel Electrolyte Lithium Batteries for LiNi0.6Mn0.2Co0.2O2 with Different Particle Sizes

Self-Assembled Surfactant-Polyoxovanadate Soft Materials as Tuneable Vanadium Oxide Cathode Precursors for Lithium-Ion Batteries

The mixing of [V10 O28 ]6- decavanadate anions with a dicationic gemini surfactant (gem) leads to the spontaneous self-assembly of surfactant-templated nanostructured arrays of decavanadate clusters. Calcination of the material under air yields highly crystalline, sponge-like V2 O5 (gem-V2 O5 ). In contrast, calcination of the amorphous tetrabutylammonium decavanadate allows isolation of a more agglomerated V2 O5 consisting of very small crystallites (TBA-V2 O5 ). Electrochemical analysis of the materials' performance as lithium-ion intercalation electrodes highlights the role of morphology in cathode performance. The large crystallites and long-range microstructure of the gem-V2 O5 cathode deliver higher initial capacity and superior capacity retention than TBA-V2 O5 . The smaller crystallite size and higher surface area of TBA-V2 O5 allow faster lithium insertion and superior rate performance to gem-V2 O5 .

Toward the efficient direct regeneration of spent cathode materials through the effect of residual sodium ions analysis

Recycling spent lithium-ion batteries is an important means for promoting sustainability within the energy industry. In this study, the effects of residual sodium on the regeneration process and the performance of spent LiNi_0.5Co_0.2Mn_0.3O₂ were explored. An appropriate amount of residual sodium was found to improve the properties of the regenerated material, with the best cycle performance and rate performance at a residual sodium of 3 mol %. The first-cycle and 100-cycle discharge capacities were 136.4 mA h g^-1 and 120 mA h g^-1, respectively, with a capacity retention rate of 87.98% after 100 cycles at a rate of 1 C. The electrochemical performance of the regenerated cathode materials was improved because sodium occupied the lithium sites in the crystal structure, providing a channel for lithium deintercalation. These results indicate that the residual sodium ions should be monitored in appropriate quantities to improve the efficiency of recycling spent lithium-ion batteries.

Gel Electrolyte for Li Metal Battery

The pursuit of high energy density enables lithium metal batteries (LMBs) to become the research hotpot again. However, the safety concerns including easy leakage and inflammability of the liquid electrolyte and the performance deterioration due to the uncontrollable Li dendrites growth in liquid electrolyte limit the further development of LMBs. Gel electrolyte, the most promising alternative for the commercial liquid electrolyte, is expected to solve the dilemma faced by the liquid electrolyte because of its higher safety, good flexibility and adaptability to the electrode and high ionic conductivity comparable to that of liquid electrolyte. Deeply understanding the characteristics and the role of the gel electrolyte in LMBs is of great importance to achieve superior electrochemical performance of LMBs. In this review, we comprehensively introduce the chemical fundamental of the gel electrolyte. On this basis, the modification strategies and the recent progress of the gel electrolyte for LMBs are systematically reviewed and particularly highlighted, which are categorized based on composition regulation, structural design and functional design. We endeavor to provide guidance for the rational design of the gel electrolyte with superior properties for LMBs.