Conventional lithium‐ion batteries (LIBs) with graphite anodes are approaching their theoretical limitations in energy density. Replacing the conventional graphite anodes with high‐capacity Si‐based anodes represents one of the most promising strategies to greatly boost the energy density of LIBs. However, the inherent huge volume expansion of Si‐based materials after lithiation and the resulting series of intractable problems, such as unstable solid electrolyte interphase layer, cracking of electrode, and especially the rapid capacity degradation of cells, severely restrict the practical application of Si‐based anodes. Over the past decade, numerous reports have demonstrated that polymer binders play a critical role in alleviating the volume expansion and maintaining the integrity and stable cycling of Si‐based anodes. In this review, the state‐of‐the‐art designing of polymer binders for Si‐based anodes have been systematically summarized based on their structures, including the linear, branched, crosslinked, and conjugated conductive polymer binders. Especially, the comprehensive designing of multifunctional polymer binders, by a combination of multiple structures, interactions, crosslinking chemistries, ionic or electronic conductivities, soft and hard segments, and so forth, would be promising to promote the practical application of Si‐based anodes. Finally, a perspective on the rational design of practical polymer binders for the large‐scale application of Si‐based anodes is presented.

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Si has been recognized as a next-generation anode alternative to graphite for high-energy-density lithium-ion batteries. However, the most intractable problem of previous Si-based anodes is the relatively low compressive strength of particles because of excess voids and porous structures, thus leading to poor structural integrity and electrochemical performance under high pressure of the rolling procedure in practical application. Therefore, a rational design of robust Si/C microspheres with a compact nano/microstructure is an effective strategy to address the abovementioned issues. In this ingenious structure, Si nanoparticles are homogeneously dispersed and anchored on flake graphite and then the composites self-assemble into microspheres via polycondensation and surface tension of pitch under high temperature and high pressure. Benefitting from this innovative approach and rational design, the obtained robust Si/C microspheres not only present high compressive property and high tap density (1.0 g cm −3 ) but also demonstrate high initial Coulombic efficiency (90.5%) and cycling stability with areal capacity (4 mA h cm −2 ) under a compaction density of 1.3 g cm −3 . Furthermore, the full cell assembled with LiNi 0.8 Co 0.1 Mn 0.1 O 2 and the resultant Si/C microsphere anode also displays good cycling performance and rate capabilities. Owing to these aspects, the proposed rational design of encapsulating Si nanoparticles in high-tap-density microspheres could be extended to load other nanomaterials for advanced batteries.

Solid‐state lithium batteries have aroused wide interest with the probability to guarantee safety and high energy density at the same time. In the past decade, fruitful endeavors have been devoted to promoting each component of these batteries, including solid electrolyte with high conductivity, dendrite‐free lithium anode, and high‐capacity cathode. However, the currently achieved cell performances are still inconsistent with the original expectations, in which interfaces severely hamper the energy output and cycling stability for practical application. Herein, particular attentions are paid to the interface between cathode and solid electrolyte. The huge resistance caused at this interface can be found throughout the entire life of batteries from preparation to operation. Accordingly, these issues are divided into physical contact, thermal interdiffusion, space‐charge layer, electrochemomechanical breakdown, and undesirable side reactions and further elucidated in detail. Moreover, representative developments concerning the cathode/solid electrolyte interface in terms of compositional and morphological control in cathode, architecture and manufacture design in solid electrolyte, and artificial interphase building are summarized. With these efforts, the emphasis of the fundamental issues and perspectives of interface between cathode and solid electrolyte may eventually contribute to high‐energy long‐cycling solid‐state lithium batteries.

Red phosphorus is appealing for anode use in sodium-ion batteries. However, the synthesis of electrochemically stable red P anodes remains challenging due to a notable volume variation upon (de)sodiation, and limited synthetic methods arising from the low ignition and sublimation temperatures. To address the above problems, we herein successfully develop an industrially adaptable process for scalable synthesis of affordable phosphorus/carbon (APC) anode materials with an excellent electrochemical performance at a significantly reduced cost. The key to our success is a delicately designed, self-organized, strongly interactive porous P/C structure filled with sodium alginate binder, which maintains the structural integrity of anode and enhances the electrical contact of red P upon its volume variation via a dual protection from porous structure and strong surface interactions. The APC anodes hence present ultrahigh initial Coulombic efficiency (86.2%), excellent cycling stability, and superior rate capability. The industrially adaptable process and excellent electrochemical performance endow the novel APC nano/microspheres with promising applications in high-performance Na-ion batteries.