The ever‐increasing demand of lithium‐ion batteries (LIBs) caused by the rapid development of various electronics and electric vehicles will be hindered by the limited lithium resource. Thus sodium‐ion batteries (SIBs) have been considered as a promising potential alternative for LIBs owing to the abundant sodium resource and similar electrochemical performances. In recent years, significant achievements regarding anode materials which restricted the development of SIBs in the past decades have been attained. Significantly, the sodium storage feasibility of carbon materials with abundant resource, low cost, nontoxicity and high safety has been confirmed, and extensive investigation have demonstrated that the carbonaceous materials can become promising electrode candidates for SIBs. In this review, the recent progress of the sodium storage performances of carbonaceous materials, including graphite, amorphous carbon, heteroatom‐doped carbon, and biomass derived carbon, are presented and the related sodium storage mechanism is also summarized. Additionally, the critical issues, challenges and perspectives are provided to further understand the carbonaceous anode materials.

A new methodology for the synthesis of carbon quantum dots (CQDs) for large production is proposed. The as-obtained CQDs can be transformed into 3D porous carbon frameworks exhibiting superb sodium storage properties with ultralong cycle life and ultrahigh rate capability, comparable to state-of-the-art carbon anode materials for sodium-ion batteries.

Large‐area phosphorus‐doped carbon nanosheets (P‐CNSs) are first obtained from carbon dots (CDs) through self‐assembly driving from thermal treatment with Na catalysis. This is the first time to realize the conversion from 0D CDs to 2D nanosheets doped with phosphorus. The sodium storage behavior of phosphorus‐doped carbon material is also investigated for the first time. As anode material for sodium‐ion batteries (SIBs), P‐CNSs exhibit superb performances for electrochemical storage of sodium. When cycled at 0.1 A g−1, the P‐CNSs electrode delivers a high reversible capacity of 328 mAh g−1, even at a high current density of 20 A g−1, a considerable capacity of 108 mAh g−1 can still be maintained. Besides, this material also shows excellent cycling stability, at a current density of 5 A g−1, the reversible capacity can still reach 149 mAh g−1 after 5000 cycles. This work will provide significant value for the development of both carbon materials and SIBs anode materials.

Designing potential anodes for sodium-ion battery with both remarkable durability and high-rate capability has captured enormous attention so far. The engineering of size and morphology is deemed as an effective manner to boost the electrochemical properties. Owing to the anisotropic self-assembly of iron selenide, rod-like FeSe 2 coates with nitrogen-doped carbon is prepared through the thermal reaction of Prussian blue with selenium. Notably, the cyano groups are effectively transformed into N-doped carbon with FeNC bonds, which uniformly coats FeSe 2 , prompting Na + transportations. Interestingly, the particle size is tailored by heating rates, along with increased carbon content, leading to broadened energy levels for redox reaction. Bestowed by these advantages, the FeSe 2 /N-C as Na-storage anode delivers impressive electrochemical properties. Even at a rather high rate of 10.0 A g −1 , a considerable capacity of 308 mAh g −1 is yielded over 10 000 loops. Supported by the detailed analysis of kinetic features, reduced size of particles could bring about the enhanced contributions of pseudocapacitive and quickening rate of ions transferring. The phase evolutions are further investigated by in situ EIS and ex-situ technologies. The work is expected to provide a new strategy to prepare metal-selenide with controllable size and induce the faster kinetic of high-rate materials.

High‐capacity cathodes and anodes in energy storage area are required for delivering high energy density due to the ever‐increasing demands in the applications of electric vehicles and power grids, which suffer from significant safety concerns and poor cycling stability at the current stage. All‐solid‐state lithium batteries (ASSLBs) have been considered to be particularly promising within the new generation of energy storage, owing to the superiority of safety, wide potential window, and long cycling life. As the key component in ASSLBs, individual solid electrolytes that can meet practical application standards are very rare due to poor performance. To the present day, numerous research efforts have been expended to find applicable solid‐state electrolytes and tremendous progress has been achieved, especially for garnet‐type solid electrolytes. Nevertheless, the garnet‐type solid electrolyte is still facing some crucial dilemmas. Hence, the issues of garnet electrolytes' ionic conductivity, the interfaces between electrodes and garnet solid electrolytes, and application of theoretical calculation on garnet electrolytes are focuses in this review. Furthermore, prospective developments and alternative approaches to the issues are presented, with an aim to improve understanding of garnet electrolytes and promote their practical applications in solid‐state batteries.