Li 2 O:Li–Mn–O Disordered Rock‐Salt Nanocomposites as Cathode Prelithiation Additives for High‐Energy Density Li‐Ion Batteries

Maria Diaz‐lopez (1, 2) , Philip Chater (2) , Pierre Bordet (3) , Melanie Freire (4) , Christian Jordy (5) , Oleg Lebedev (4) , Valérie Pralong (4)

1 ISIS Facility
2 DIAMOND Light source
3 NEEL - MRS - Matériaux, Rayonnements, Structure
4 CRISMAT - Laboratoire de cristallographie et sciences des matériaux
5 SAFT [Bordeaux]

The irreversible loss of lithium from the cathode material during the first cycles of rechargeable Li-ion batteries notably reduces the overall cell capacity. Here, a new family of sacrificial cathode additives based on Li2O:Li2/3Mn1/3O5/6 composites synthesized by mechanochemical alloying is reported. These nanocomposites display record (but irreversible) capacities within the Li–Mn–O systems studied, of up to 1157 mAh g−1, which represents an increase of over 300% of the originally reported capacity in Li2/3Mn1/3O5/6 disordered rock salts. Such a high irreversible capacity is achieved by the reaction between Li2O and Li2/3Mn1/3O5/6 during the first charge, where electrochemically active Li2O acts as a Li+ donor. A 13% increase of the LiFePO4 and LiCoO2 first charge gravimetric capacities is demonstrated by the addition of only 2 wt% of the nanosized composite in the cathode mixture. This result shows the great potential of these newly discovered sacrificial additives to counteract initial losses of Li+ ions and improve battery performance.

Mots clés: Cation-disordered; Rock salts; Initial capacity losses; Li4Mn2O5; Lithium batteries; Sacrificials

Domaines: Chimie

Maria Diaz‐lopez, Philip Chater, Pierre Bordet, Melanie Freire, Christian Jordy, et al.. Li 2 O:Li–Mn–O Disordered Rock‐Salt Nanocomposites as Cathode Prelithiation Additives for High‐Energy Density Li‐Ion Batteries. Advanced Energy Materials, 2020, 10 (7), pp.1902788. ⟨10.1002/aenm.201902788⟩. ⟨hal-03451746⟩