Materials, electrodes and electrolytes advances for next-generation lithium-based anode-free batteries

Abstract

The high volumetric stack energy density (∼ 750Wh L−1) is a must for grasping the practical application of electric vehicles with more than 100 km per day driving range. Such achievement requires significant advances in state-of-the-art battery technologies. The anode-free, derived from the metal-battery concept, germinates as one of the future potential battery configurations due to the highest, nearly theoretical gravimetric and volumetric energy density. Thus, moving from the graphite-based anode, where lithium is stored as ions, to anode-free cells, wherein lithium is plated as metal, can change the scenario of the electrochemical energy storing devices both in terms of energy density and fundamental mechanism. Although an anode-free battery theoretically provides higher stack energy density than a Li-ion battery, current developments are still underoptimized as these can barely hold for several cycles at room temperature due to the absence of an active lithium reservoir and still severe losses at the anode side. Hence electrolyte engineering with suitable electrode material choice is highly desirable and extremely challenging in realizing next-generation anode-free batteries. Herein, we summarize the current developments and achievements in the direction of anode-free batteries. Central emphasis is set on electrolyte chemistries that should on one hand allow for high-efficiency initial nucleation, followed by subsequent electrodeposition and electrodissolution of lithium metal, while also forming stable anodic interphases with the high energy cathode materials currently in use. We also prospect for better batteries with higher energy density beyond the present status.

Lithium-Ion Battery Manufacturing: Industrial View on Processing Challenges, Possible Solutions and Recent Advances

“…Another promising approach for the stacking of SSBs is an anode-free design, in which lithium is deposited onto the current collector during the first cycle of the battery [101], skipping the usage and the stacking of the lithium-metal foil during the assembly step and enabling milder dry room conditions in which to work. In addition, it does not require high CAPEX for equipment since, theoretically, already available equipment tooling and processing infrastructure can be used.…”

Dual‐Ion Intercalation Chemistry Enabling Hybrid Metal‐Ion Batteries

“…All these features evidence that HMIBs combine the advantages of single-ion batteries and HRBs. In comparison with single-ion rechargeable batteries, the dual-salt electrolytes in HMIBs play multiple roles: [27] (i) The dual-salt electrolytes are characterized by improved ionic conductivity, viscosity, and thermal stability compared with the single-salt ones; (ii) The dual-salt electrolyte extends, in some cases, the electrochemical stability windows of the single-salt ones; (iii) The dual-salt electrolytes have a strong impact on the formation of electrode/electrolyte interface; [28,29] (iv) The dual-salt electrolyte directs redox reactions in desired track. [30] Therefore, the challenge in the design of HMIBs is to find the right electrode materials, as well as to understand the chemistry of electrolyte containing more than one cation.…”

Conditioning Solid-State Anode-Less Cells for the Next Generation of Batteries

“…To achieve these objectives, there is increasing research in developing batteries that do not contain hazardous or environmentally harmful materials while maintaining high safety standards [3]. A promising approach is using anode-less battery configurations, particularly those utilizing solid-state electrolytes [4,5].…”