If we must answer your question, the answer will be a straightforward "we don't know". We can't determine the compatibility of the battery based on the data provided by aliexpress store, and we don't even know if their data is reliable. The only way to do that is to buy a few samples (not less then 5) and run a series of test to determine the physical dimension (and variation), electrical characteristic and safety measurements of the battery. I don't think there is any consumer electronic manufacture will do that Certify an unbranded aftermarket Lithium battery as acceptable replacement is a very high risk procedure, we simply can't take the risk of having a third-party Lithium battery exploded in N3 while charging and playing and then the battery is somehow "certified" by Cayin.
There are several factors that affect the life of a Lithium-ion battery. For example, partial or swallow discharge pattern reduces stress and prolongs battery life, deep discharge pattern will, on the other hand, increase stress and shorten batter life.
This article explains how Depth of Discharge (DOD), temperature and charging current will affect the "Cycle" life of a Lithium battery. For the records, we have sold over 10,000 units of N3 already, and over 50% were sold in 2017 (first six months of launch to be exact), Majority of these players are still running with an acceptable batter performance. Be reminded that domestic customer can send their N3 tou us at $3 to $10 only, so if the battery replacement cost is very low to them, and yet we only received a handful of battery replacement request so far.
If you must replace the battery of your N3, you have to send the player back to the factory in China. You can either do that through your local Cayin dealer or email
service@cayin.cn for more detail.