>>the UK consumer is the cause for those emissions.
Sure, but counting it as UK emissions would mean you count it twice, no? If other countries that mine lithium report their own CO2 emissions then if you add the CO2 cost of using electronics made with lithium and used in UK to UK's CO2 emission, that means you have counted the same emissions twice,no?
While there's a lot of nuance to this: in carbon accounting it is standard practice to account for the same emission more than once. Carbon inventories are broken out into three different scopes, the first two scopes concern fuel and electricity generation emissions, and the third scope includes everything in your value chain (both upstream and downstream). Therefore the country producing the EV battery would report on the emission in their Scope 1 and Scope 2 inventory, and the country utilising that EV battery would report it within their Scope 3 inventory.
It may seem odd to double account, but the goal of carbon accounting is not to ascribe blame to an emission (since ascribing blame is a never-ending game of finger pointing), it is to make every business/consumer responsible. The country creating the emission needs to be incentivised to decarbonise, and the country consuming that emission needs to be incentivised to decarbonise their full - including international - supply chains.
It *should* include all scopes, including upstream emissions from purchased goods and services from abroad. But in many countries their country-level carbon inventories still have huge gaps.
UK Legislation implements the GHG Protocol scope system in the UK's carbon accounting regulations that businesses must follow for reporting their emissions (e.g. SECR), and government guidance for calculating emissions all follow the scope system too (e.g. BEIS Conversion Factors guidance). So it is very disappointing if the UK's carbon accounts has got gaps (but I wouldn't be surprised).