Battery cell, battery, and electrical device

A battery cell, comprising:

• an end cap assembly, comprising an electrode terminal;
• a housing, on which an opening is created, wherein the end cap assembly seals the opening;
• an electrode assembly, disposed in the housing, wherein the electrode assembly comprises a tab;
• an adapter component, connected between the tab and the electrode terminal, wherein the adapter component comprises a first connecting region configured to be connected to the electrode terminal, a second connecting region configured to be connected to the tab, a transitional connecting region located between the first connecting region and the second connecting region, and an embossed region comprising a plurality of friction bulges, the first connecting region is located inside the embossed region, and a friction coefficient of the embossed region is greater than a friction coefficient of a region of the adapter component other than the embossed region;
• and
• an insulation piece, covering at least a part of the transitional connecting region.