Multilayer assembly

A multilayer assembly comprising:

• a metallic layer (a) consisting essentially of lithium metal or its alloys with silicon or tin, said metallic layer (a) comprising a first surface and a second surface;
• and
• a coating layer (b) which adheres to at least one of said first surface and second surface of metallic layer (a),
• wherein a thickness of the coating layer (b) ranges from 2 to less than 5 micrometers,
• wherein (b) comprises a hybrid inorganic/organic composition obtained by reacting:
• i. a compound (M) of formula (I)
• X4-mAYm (I)
• wherein X is a hydrocarbon group, optionally comprising one or more functional groups, m is an integer from 1 to 4, A is an element selected from the group consisting of Si, Ti and Zr, and Y is a hydrolysable group selected from the group consisting of an alkoxy group, an acyloxy group and a hydroxyl group with
• ii. at least one fluoro co-polymer (F), that comprises recurring units derived from vinylidene difluoride (VDF) and recurring units derived from at least a monomer (R1′) having at least one group —O—Rx and/or —C(O)O—Rx, wherein each Rx, optionally independently from the others, is a hydrogen group or a C1-C5 hydrocarbon group comprising at least one hydroxyl group,
• wherein by reaction of the compound (M) and the fluoro co-polymer (F), inorganic residues derived from polycondensation of compound (M) are at least partially chemically bound to co-polymer (F) via reaction with the groups —O—Rx and/or —C(O)O—Rx of co-polymer (F), and wherein (b) comprises:
• electrolyte salt (ES-1);
• and
• an ionic liquid (IL-1);
• wherein the multilayer assembly is made by coating at least one of the said first surface and second surface of metallic layer (a) with the hybrid inorganic/organic composition, so as to obtain a coated layer, and
• wherein the multilayer assembly exhibits lower lithium dendrite growth than a multilayer assembly having a reference coating layer of the at least one fluoro co-polymer (F) without the compound (M).