Turning commercial MnO2 (≥85 wt%) into high-crystallized K+-doped LiMn2O4 cathode with superior structural stability by a low-temperature molten salt method

Confinement of ZIF-67-derived N, Co-doped C@Si on a 2D MXene for enhanced lithium storage

A heterostructure composed of ZIF-67-derived nitrogen and cobalt-doped carbon enfolded silicon (C@Si) nanoparticles anchored on 2D MXene layers was constructed for boosting the performance of lithium-ion batteries (LIBs). The heterostructure anode demonstrated a high initial discharge capacity of 3021 mA h g-1 at 0.2 A g-1, retaining outstanding cycling stability with a reversible capacity of 520 mA h g-1 at 2000 mA g-1, and the coulombic efficiency remained above 97% after 500 cycles. The introduced Ti3C2 nanosheets and the cobalt-doped carbon can not only contribute to the interfacial transfer of Li+ and electrons but also buffer the volume expansion of Si.

Achieving Cycling Stability in Anode of Lithium-Ion Batteries with Silicon-Embedded Titanium Oxynitride Microsphere

Surface coating approaches for silicon (Si) have demonstrated potential for use as anodes in lithium-ion batteries (LIBs) to address the large volume change and low conductivity of Si. However, the practical application of these approaches remains a challenge because they do not effectively accommodate the pulverization of Si during cycling or require complex processes. Herein, Si-embedded titanium oxynitride (Si-TiON) was proposed and successfully fabricated using a spray-drying process. TiON can be uniformly coated on the Si surface via self-assembly, which can enhance the Si utilization and electrode stability. This is because TiON exhibits high mechanical strength and electrical conductivity, allowing it to act as a rigid and electrically conductive matrix. As a result, the Si-TiON electrodes delivered an initial reversible capacity of 1663 mA h g^-1 with remarkably enhanced capacity retention and rate performance.

Expanded K0.37Fe0.04Al0.07Mn0.89O2 Layered Material as a High-Performance Cathode in Sodium-Ion Batteries

Due to a high operating voltage and theoretical capacity, P2-type layered Mn-based metal oxides are considered to be promising cathodes in sodium-ion batteries, but their poor structural stability in the process of Na+ insertion/deinsertion severely hinders their practical application. Here, an interesting K+ pre-intercalation is used to expand the interlayer distance and enhance the electrochemical reversibility of KsFexAlyMnzO2. With a suitable K+ content, the optimized electrode shows a high specific capacity of 135 mAh g−1 at 0.1 C, a good rate capability of 80 mAh g−1 at 5 C and an excellent cycling performance of 76.4% capacity retention after 200 cycles at a high rate of 5 C. This work proves the feasibility of a K+ pre-intercalation strategy in a P2-type layered cathode.