Compensation of the Irreversible Loss of Si-Anodes via Prelithiated NMC/LMO Blend Cathode

Abstract

Silicon-containing anode materials are an emerging market for commercial Lithium-Ion batteries. However, their main benefit of high specific capacity is partly negated by a relatively high irreversible capacity loss during the first formation cycles. One strategy to mitigate this problem is a dedicated prelithiation-step for the silicon containing anode. However, this comes with technical difficulties and additional costs. As a straightforward alternative, a simple chemical prelithiation method is presented by prelithiation of manganese spinel used as a cathode material. This additional Lithium in the cathode layer is capable of compensating for the initial capacity-loss during formation. Furthermore, we applied this concept of cathode blends to further improve energy density and rate capability. By choosing the correct blending ratio of cathode materials including prelithiated manganese spine, higher specific energy than conventional layered oxides can reach in full cell, reducing unutilized material usage in the cell, and therefore costs with offering higher energy content.