Silicon anodes offer a very promising approach to boost the energy density of lithium-ion batteries. While silicon anodes show a high capacity and, depending on the system, a good cycle stability in half-cells vs lithium, their integration in industrially applicable lithium-ion full-cells is still challenging. Balancing described as the capacity ratio of negative and positive electrode (n/p ratio) is a crucial necessity for the successful design of lithium-ion batteries. In this work, three different silicon based anode systems, namely carbon coated silicon nanowires, columnar silicon thin films and silicon-carbon void structures are compared in LIB full cells containing NMC111 cathodes. By varying the areal capacity of the NMC111 cathode, the influence of the balancing was investigated over a broad n/p range of 0.8−3.2. The aim was to find an ideal compromise between lithium plating suppression, high cycling stability and maximized energy density. To underline the high volumetric energy density, the columnar silicon thin films are additionally analyzed in multilayered pouch cells with NMC622 and NMC811 cathodes resulting in 605 Wh L−1 and 135 Wh kg−1 and even 806 Wh L−1 and 183 Wh kg−1 as demonstrated on stack level.

In recent years, both silicon thin films and nickel-rich layered oxides have received much attention as promising anode or cathode materials for next generation lithium ion batteries, respectively. In this work, full cells containing Li[Ni 0.8 Co 0.1 Mn 0.1 ]O 2 (NCM811) as cathode in combination with amorphous columnar silicon thin films as anode are evaluated in coin cells and 3-electrode cells with varying capacity balancing. Full cells with area capacity ratios of negative to positive electrodes (n/p-ratio) reaching from 1.15 : 1 to 2.70 : 1 are studied. The cells with a high n/p-ratio (2.00 : 1 and 2.70 : 1) show significantly lower specific capacity of 115 mA h g NCM −1 after 50 cycles of galvanostatic cycling in comparison to 130 mA h g NCM −1 for a cell with a n/p-ratio of 1.15 : 1. One reason for this phenomenon is the decline of the initial coulombic efficiency with increasing n/p-ratios. Secondly, through only partial utilization of the silicon anode by using high n/p-ratios, the anode potential is increased at the end of charge. This leads to a higher cathode potential and therefore a faster degradation of the cell. In summary, for designing high performance NCM811/Si full cells, high n/p-ratios should be avoided.

Due to a void structure the stability of the Si–C anode increased and it was coupled with a sulfur cathode.