In I Am China by Xiaolu Guo, how can Jian's loss of identity be explained, and what role does his status as an asylum-seeker play?

To properly answer this question, let us establish a bit of context with respect to the setting and main characters.
Kublai Jian (along with his love interest, the poet Deng Mu) is one of the main characters in Xiaolu Guo's novel I Am China. When the story begins, just after the historic events of Tiananmen Square have unfolded, Jian is a punk rocker living in Beijing.
The third character at the center of this book is a literary translator named Iona Kirkpatrick. She works for a publishing house in London, and she is in the process of sorting through and translating Jian's letters and diaries. In reading these materials, she learns about the two-decade-long love story between Jian and Mu. She realizes that they have been separated (though she does not know how at first, she will eventually learn that Jian is at a psychiatric hospital in England, seeking asylum, while Mu is searching for Jian back in Beijing) and feels increasingly compelled to find them and help them to reunite.
Now, to get back to the question at hand. How can we explain Jian's loss of identity? To what extent is his status as someone seeking asylum important?
First, let us talk about Jian's identity in general and how it changes in the course of the narrative. Jian is living in Beijing when the book opens. He is not fully Chinese, however: he identifies as half Mongol and half Han Chinese. There is something essentially disorienting about his identity, even before he leaves China and ends up going to live for stints in Switzerland and France before seeking asylum in the UK. His constant dislocation, both physical and emotional (he is separated from Mu, as she is touring internationally as a poet while he is jumping from one country to the next), means that he has already lost a sense of identity before he ever gets to England.
The reason for Jian's departure from China, too, is a major contributor to his loss of identity. As Iona discovers in her translations, Jian wrote a political manifesto that forced him to go into exile. The last lines of that manifesto inspired the title of the book, and they also speak to Jian's estrangement from his native country:

I am China. We are China. The people. Not the state.

So, how does Jian's status as someone seeking asylum play into his loss of identity? On one hand, being in exile frees him from the expectations and norms of the place he is from. However, he does not have any particular status in the place where he seeks asylum. He is isolated and alone, and he struggles internally with his political ideals and his personal nostalgia for the place he used to call home. This is well expressed in one of his letters to Mu that Iona translates:

Dearest Mu, The sun is piercing, old bastard sky. I am feeling empty and bare. Nothing is in my soul, apart from the image of you. I am writing to you from a place I cannot tell you about yet.

Being a seeker of asylum renders him vulnerable and even weak—he is at the mercy of the system. It is worth mentioning that the author herself, Chinese by birth, has been living in England since 2002. This novel is in part a product of her personal experience.