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Silicon oxide (SiOx) is recognized as a promising anode material for high-energy lithium-ion batteries (LIBs) due to its abundant reserves, facile synthesis, and high theoretical capacity. However, the practical use of the SiOx anode is severely hampered due to its poor cycling stability caused by a large volume change upon lithiation/delithiation. The waterborne poly(acrylic acid) (PAA) binder has been regarded as one of the most promising binders for SiOx-based anodes. In this work, a new concept is developed using locally an enriched PAA binder to enhance the structural stability of the electrode, the adhesion force between the electrode and the current collector, and the dispersion of carbon black within the electrode. By simply replacing water with an organic solvent (for example, N,N′-dimethyl formamide, DMF), the PAA binder is enriched locally in DMF because the PAA chains collapse in the DMF solution, leading to an increased functional group density. Improved electrochemical performance in terms of capacity retention and rate capacity is achieved by the locally enriched PAA binder in both half-cell and full-cell configurations. In detail, the SiOx/PAA-DMF‖Li half-cell exhibits a high reversible capacity with enhanced long-term cycling stability (1447 mA h g−1 at 0.5 C for over 100 cycles with 84.5% capacity retention). The LiFePO4‖SiOx full-cell test shows that the capacity retention is increased from 62.4% to 74.4% after 200 cycles at 0.5 C. This work establishes a new concept practically feasible for applications of the alloying-based lithium-ion battery anode. [ABSTRACT FROM AUTHOR]

Titanium dioxide of bronze phase (TiO2(B)) has attracted considerable attention as a promising alternative lithium/sodium‐ion battery anode due to its excellent operation safety, good reversible capacity, and environmental friendliness. However, several intrinsic critical drawbacks, including moderate electrochemical kinetics and unsatisfactory long cyclic stability, significantly limit its practical applications. It is crucial to develop reliable strategies to resolve these issues to advance the TiO2(B) based materials into practical applications in lithium/sodium‐ion batteries. In this review, both the theoretical and experimental investigations on the TiO2(B) based materials over the last few decades are chronically elaborated. Insights on the general and detailed evolution trends of the research on TiO2(B) anodes are provided. The review also points to future directions for the TiO2(B) anode research to advance the practical application of TiO2(B) anodes. [ABSTRACT FROM AUTHOR]

Binders play an important role in multi-component electrodes for rechargeable batteries based on various elements such as Li, Na, K, Mg, and Zn, which suffer from poor electronic and ionic conductivity. Binder-free electrodes provide another way to resolve problems, where sophisticated structure construction is required. A new concept of electrode processing alternative to binder-containing and binder-free electrodes was established. A multi-functional PIM-1 (a polymer with intrinsic microporosity) additive was used instead of PVDF to form mechanically processable lithium secondary battery cathodes free of dissolution of PIM-1. Due to its unique nanoporous structure built by the spiro-containing rigid aromatic polymer chain, only a tiny amount of PIM-1 is needed to retain good performance (from 1% to 0.05%), far below the typical composition for PVDF. The universal applicability of PIM-1 to cathodes of LiNi0.8Co0.1Mn0.1O2, LiNi0.5Co0.2Mn0.3O2, LiFePO4, and LiCoO2 is demonstrated. Homogeneous dispersion of carbon black is achieved by PIM-1 via a point-to-plane contact mode, which stabilizes the electrode and increases the electronic conductivity. Mechanical buffering by stiff PIM-1 yields crack-free electrodes after cycles. An inorganic rich cathode-electrolyte interface layer is formed via a desolvation process promoted by PIM-1, because of its strong binding ability with lithium ions, which is beneficial for cyclic stability and rate capability. [ABSTRACT FROM AUTHOR]