From Active Materials to Battery Cells: A Straightforward Tool to Determine Performance Metrics and Support Developments at an Application‐Relevant Level

Abstract

batteries are currently the most powerful energy storage technology, particularly for powering mobile electronic devices and electric vehicles. [1][2][3] Improved Li-ion batteries and alternatives, such as Li-metal batteries, [4] Li-S batteries, [5] and solid-state batteries, [6] have the potential to effectively address current civilization challenges such as global warming, environmental pollution, and depletion of fossil fuel resources, paving the way to a sustainable future. To this end, academia and industry around the world are conducting intensive research into various ways to improve existing batteries or bring novel concepts into application. The development of advanced materials and electrodes is one of the most important steps in this process. [7][8][9][10] On a daily basis, reports of improved active materials or electrode architectures that significantly outperform established batteries are published in the scientific literature. However, the transfer of these innovations into practical application is rather rare. This may be due to difficulties in scaling the corresponding production routes to an industrially relevant level. Another possible reason is that promising performance metrics at the material level are not achieved in practical batteries, due to the different definition of performance parameters at the different technological levels, i.e., material, electrode, cell, system, etc.Various renowned scientists have already addressed these shortcomings in the presentation of performance data of new battery materials and electrodes in scientific literature [6,[11][12][13][14][15] and explicitly alert that extraordinary power claims for components used in batteries often do not hold up at the device level. These authors emphasize that reporting energy and power densities per weight of active material or electrode alone does not provide a realistic picture of the performance that an assembled device could achieve because it does not consider the weight of other necessary components. For example, it is well known that the rate capability scales with the electrode thickness. [16][17][18] Very thin electrodes (<20 µm) can be charged in a few minutes whereas thick electrodes (>100 µm) need several hours to achieve full capacity. When considering the specific capacity obtained at high rates in terms of mAh g -1 with respect to the mass of active material, the thin electrodes clearly outperform the thick ones. However, considering the power density Large-scale electrochemical energy storage is considered one of the crucial steps toward a sustainable energy economy. Science and industry worldwide are conducting intensive research into various ways to improve existing battery concepts or transferring novel concepts to application. The development of materials and electrodes is an essential step in this process. However, the evaluation of the achieved performance parameters and the comparison of the different studies at this technological level with regard to practical applications is challenging, since spec...

Benchmarking and Critical Design Considerations of Zero‐Excess Li‐Metal Batteries

“…Different cell types (pouch, cylindrical prismatic, bipolar configuration, …) have different cell‐utilization‐factors that furthermore depend on the number of layers (stacks), design of tabs, etc. To keep our statements as general as possible, we consider the single cell element level, [ 17 ] including current collectors, electrode layers, electrolyte, and separator. We would like to stress that our analysis only considers the nominal energy density and neglects any effects of the modifications on other important properties, such as safety, rate capability, and cycling stability.…”

Anode‐Free Lithium Metal Batteries Based on an Ultrathin and Respirable Interphase Layer

“…Ragone plot highlighted the advantages of our anode‐free batteries in energy and power densities (up to 527 Wh kg −1 and 1554 W kg −1 , respectively, based on the total mass of active materials on both cathode and anode) compared with state‐of‐the‐art LMBs based on LFP [45, 56] and other high‐energy‐density cathodes such as LiCoO 2 [13] and LiNi 0.5 Mn 0.3 Co 0.2 O 2 (NMC532, Figure 5c). [57] With the use of ultrathin current collector/separator and low‐density electrolyte, the energy and power densities of our anode‐free batteries can be further promoted at the cell level [58] . More efforts are still underway for further improvement.…”

“…batteries can be further promoted at the cell level. [58] More efforts are still underway for further improvement.…”

Anode‐Free Lithium Metal Batteries Based on an Ultrathin and Respirable Interphase Layer

“…Chemie batteries can be further promoted at the cell level. [58] More efforts are still underway for further improvement.…”