The development of rechargeable batteries with high‐energy density is critical for future decarbonization of transportation. Anode‐free Li‐ion batteries, using a bare current collector at the anode side without any excess of Li, provide the highest volumetric energy density (>1500 Wh L⁻¹) among all possible cell configurations. Furthermore, elimination of the anode material coating reduces material consumption and greatly simplifies cell production, which in turn lowers costs. Although significant progress has been made recently by the application of modified current collectors, optimized cycling parameters and improved liquid electrolytes, insufficient efficiencies, and dendritic growth during lithium plating lead to poor cycle life of typically less than 100 cycles as well as safety issues. Alternatively, very recent studies have demonstrated anode‐free solid‐state batteries that combine the benefits of high energy anode‐free cell configuration and solid‐state systems with high safety, exceeding 1000 cycles. This review provides an overview of recent developments toward anode‐free solid‐state batteries and highlights the current issues and challenges in this nascent field. It is concluded that, although major challenges remain at the present, the lessons learned in the fields of liquid electrolytes and solid‐state lithium metal batteries can accelerate the development of anode‐free solid‐state batteries of practical relevance.

The continuing rise of electric mobility is driving demand for lithium‐ion batteries to unprecedented levels. To ensure efficient production of high quality, yet affordable battery cells, while making the best use of available raw materials and processes, reasonable quality assurance criteria are needed. A step of particular importance, affecting all downstream processes, lies in electrode manufacturing including mixing, coating, drying, and calendering. Several classes of defects which originate in these processes are well‐known and detectable using various methods. The crucial point, however, lies in the quantification of their electrochemical significance, i. e., in an evaluation, which defect types, sizes and concentrations can be tolerated without impacting cell performance. Herein, we review the still scarce literature on that topic. It is found that, although the impact of some defects is quite well understood, others almost completely lack an evaluation of their criticality. We finally make suggestions for further studies paving the way to deduce knowledge‐based quality assurance criteria for the large variety of coating defects occurring in lithium‐ion battery electrodes.

Blended electrode materials containing high‐capacity silicon (Si) and robust graphite (Gr) materials are considered advanced alternatives to pure graphite electrodes used in Li‐ion batteries. Understanding the component‐specific lithiation and delithiation behavior and electrochemical interactions between the blended materials is of crucial importance for targeted optimization of composition and microstructural design, yet hardly addressed to date. Herein, a model‐like Si/Gr blended electrode and special electrochemical cell are introduced to directly capture the component specific behaviors for the first time. This includes studies of the formation cycles, the reaction distribution between Si and Gr, the component‐specific contributions to the capacity at different charge and discharge rates, and the internal dynamics during pulse loads and subsequent relaxation. The deconvolution of the components’ behavior during operation provides fundamental insights that contribute to a profound understanding and targeted optimization of Si/Gr blended electrodes. Furthermore, the application of the presented experimental approach can serve scientists to identify and study other advanced materials combinations as blended electrodes for rechargeable batteries.