The uniqueness of the Co3O4/N-doped carbon nanospheres derived from a metal–organic framework offers new functional materials for lithium (ion) battery applications.

Exfoliating graphite to graphene has attracted great attention due to the fantastic properties of graphene available for designing graphene-based materials or devices. Besides the classic solution method, herein a unique role of TiO 2 in exfoliating graphite to be graphene layers effectively is reported. As a paradigm, this discovered effect of TiO 2 is significant for preparing highperformance graphene-modified SiO x -based anode in lithium-ion batteries (LIBs), in which the graphite is in situ exfoliated mechanically by TiO 2 to be multilayered graphene (i.e., MLG) and then the SiO x is wrapped by the MLG to construct a SiO x /TiO 2 @MLG. In this case, an extremely high capacity of 1484 mAh g −1 , long lifespan over 1200 cycles at 2 A g −1 , as well as good performance in full LIBs (vs nickel-rich cathode) are demonstrated. It is confirmed that the MLG can enhance electric conductivity, mitigate electrolyte decomposition, and alleviate volume effect of the SiO x effectively. This result is hard to be achieved using other kinds of metal oxide besides TiO 2 . It is hoped that the SiO x /TiO 2 @MLG is practical for pursuing LIBs with an energy density beyond 300 Wh kg −1 . In addition, it is believed the ingenious strategy is applicable for designing more functional materials with greater capabilities.

New hierarchical hollow SiO2 spheres decorated with metal nanoparticles were designed by using an in situ self-assembly approach for lithium-ion battery applications.

The nucleation and growth of spherical Ni0.6Co0.2Mn0.2(OH)2 agglomerates using the hydroxide coprecipitation (HCP) method in the presence of ammonia is investigated through chemical equilibrium calculations and experiments. In the nucleation stage, the transition metal ions in the salt solution gradually complete the nucleation reaction in the diffusion process from pH 5.4 to 11 after dropping into the continuously stirred tank reactor, and then Me­(NH3) n 2+ and Me­(OH)2(s) (Me: Ni, Co, and Mn) reach a dynamic precipitation dissolution equilibrium. In the growth stage, the concentration ratio of Me­(NH3) n 2+ and OH– (complexation and precipitation, R c/p) in the solution has an important influence on obtaining high-quality materials, which is further confirmed using the first principles density functional theory calculations on surface energy and adsorption energy. Then, the HCP reaction could be divided into three parts through experiments: incomplete precipitation area (R c/p > 10.1); time-dependent area (R c/p = 0.1–10.1); and hard-to-control area (R c/p <0.1). According to the optimal ratio (R c/p = 3.4), a prediction formula for the optimal synthesis conditions of the materials is proposed (y = 0.7731 × ln­(x + 0.0312) + 11.6708, the optimal pH value (y) corresponds to different ammonia concentrations (x)). The results obtained for the growth reaction mechanism and the prediction scheme would help the modification research of the materials and obtain the desired lithium-layered transition metal oxide cathode material with excellent performance in the shortest time.

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Rate-limited formation of low-stage intercalation and lithium precipitation at high C-rate severely limited the application of graphite anode for fast-charging lithium ion batteries (LIBs). Exploration of new-type fast-charging anodes is...

Carbon nanotubes (CNTs) modification is one of the most important strategies to boost the performance of materials in various applications, among which the CNTs modified silicon-based anodes gain great attention...

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